
Caster
Mostima
★★★★★★
Laterano
Introduction
Mostima is a 6-star character in Arknights. Mostima's class is Caster. Faction: Laterano.
On the combined Arknights tier list Mostima is B tier, 94th of the 410 characters ranked, from where 3 community tier lists put Mostima.
What Mostima does
Speeds up SP for every
Caster on the field and slows enemies in her range by 18%. Her second skill Stuns everything in range while dealing 140% ATK as Arts damage each second, and her third turns her attacks into spreading ripples with 170% more ATK, a tripled Slow and a light knockback.
Mostima's banners
All banners- 28 July 2026 to 11 August 2026Rare Operators useful in all kinds of stages
- 30 June 2026 to 14 July 2026 Celebration - Kernel
- 10 February 2026 to 24 February 2026Rare Operators useful in all kinds of stages
- 21 October 2025 to 4 November 2025Rare Operators useful in all kinds of stages
- 1 July 2025 to 15 July 2025 Celebration - Kernel
- 3 June 2025 to 17 June 2025Rare Operators useful in all kinds of stages
- 6 May 2025 to 20 May 2025Rare Operators useful in all kinds of stages
- 5 November 2024 to 19 November 2024Rare Operators useful in all kinds of stages
- 13 August 2024 to 27 August 2024Rare Operators useful in all kinds of stages
- 2 July 2024 to 16 July 2024 Celebration - Kernel
- 21 May 2024 to 4 June 2024Rare Operators useful in all kinds of stages
- 26 March 2024 to 9 April 2024Rare Operators useful in all kinds of stages
- 5 December 2023 to 19 December 2023Rare Operators useful in all kinds of stages
- 14 July 2023 to 28 July 2023Celebration & Link-Up
- 15 July 2022 to 29 July 2022Celebrate & Recollect
Profile
Her birthday is Dec 12, and she stands 170cm tall. Mostima is voiced by Luttefair in Chinese, Kira Buckland in English, Nana Mizuki in Japanese, and Park Seon-young in Korean. 幻象黑兔 drew her.
Stories
9Basic Info
[Code Name] Mostima
[Gender] Female
[Combat Experience] 1 Year
[Place of Birth] Laterano
[Date of Birth] Dec 12
[Race] Undisclosed
[Height] 170cm
[Infection Status]
Medical tests have confirmed that no infection is present.
Physical Exam
[Physical Strength] Standard
[Mobility] Standard
[Physical Resilience] Standard
[Tactical Acumen] Standard
[Combat Skill] Excellent
[Originium Arts Assimilation] Excellent
Profile
An employee of Penguin Logistics who always acts alone. Nothing is known about her previous work history.
Clinical Analysis
Imaging tests reveal clear, normal outlines of internal organs, and no abnormal shadows have been detected. Originium granules have not been detected in the circulatory system and there are no other signs of infection. At this time, this operator can be confirmed to be uninfected.
[Cell-Originium Assimilation] 0%
Operator Mostima shows no signs of Oripathy infection.
[Blood Originium-Crystal Density] 0.12u/L
As a transporter, Operator Mostima frequently enters dangerous environments. However, it goes without saying that she knows how to protect herself.
Archive File 1
A transporter who always wears a smile on her face.
She is well-informed and well-traveled, having a good understanding of the geography and customs of most countries in Terra. She often drops facts about various places that would be considered secrets to outsiders. However, tracking her down can be as hard as chasing a ghost, and no one seems to be able to find her when she's needed.
She can get along with just about everyone, but also seems to keep her distance at the same time.
Archive File 2
Many consider Ms. Mostima to be a black box.
First of all, just being able to find her is no small feat.
Second, even if they manage to talk to her, some say that they feel as if they are talking to the air. Regardless of if they're thanking her, admiring her, swearing at her, or piling hatred upon her, she seems to only respond by curling the corners of her lips into a wry smile, answering with a normal demeanor as if she felt no emotions.
And Ms. Mostima herself made it clear that regarding emotions, she 'doesn't hate them, but has no need for them.' Her words reflect a remarkable nonchalance. This is an important reason why many consider her to be more terrifying than even less personable colleagues. Whether her personality is a result of her past, or simply a numbness derived from many long years of work as a transporter, we may perhaps never know.
Archive File 3
As a veteran transporter, Ms. Mostima often has some logistics commissions that require her to go to remote or even dangerous places, so she will often not be aboard the Rhodes Island ship - terms that have been specified in her onboarding contract.
In fact, very few Operators are actually standing by on the ship at all times. Once the Rhodes Island ship has docked at a certain location, Operators are free to carry out activities in the locale as long as they maintain contact with the ship and do not act in a way that would damage the interests of Rhodes Island.
Beyond this point, however, Ms. Mostima also has a few peculiarities. According to the application she submitted, Ms. Mostima often proactively seeks out delivery orders that would require her to travel abroad. Usually, Rhodes Island couriers will only operate in a local vicinity, because the time and risk involved in long-distance travel is a serious consideration for even the most experienced in the industry. Yet it doesn't seem to concern Ms. Mostima.
Does this mean that she has a special reason for doing so?
Archive File 4
According to the resume submitted by Ms. Mostima, she worked as a transporter throughout all of Terra, but mentioned nothing else beyond that.
Why would she provide her services for Penguin Logistics, why did she already know Ms. Exusiai, and most importantly, why did she become a fallen angel? Even though Ms. Mostima seems to have integrated well into Rhodes Island and has even established trust with the Doctor, she is still a complete mystery in the eyes of many.
Following the guideline that, outside of extraordinary situations, we are not to pry excessively into the history of our Operators, Rhodes Island has no plans to seek answers to each and every one of these questions. However, one truth is very clear.
The Law is absolute. From the moment she aimed her gun at another of her kind, her fate was already decided.
This is a publicly known secret.
Promotion Record
In addition to her past experience, there is another noteworthy thing about Ms. Mostima, and that is her ability. Her two staves, known as 'Black Lock' and 'White Key' respectively, can cast very different spells. This is an extremely rare phenomenon, and her explanation of this is preliminary at best.
There is no doubt that Ms. Mostima's powers are unfathomable. According to the judgment of Chief Engineer Kal'tsit at the time she tested Ms. Mostima's abilities, Rhodes Island's training facilities would have been destroyed if she had put more effort into the testing. Such is the terrifying scale of her power.
More importantly, though, what was the monstrosity that appeared behind her at the moment the two forces within her hands overlapped?
Stats
- HP217th of 4551,831
- ATK70th of 455834
- DEF317th of 455132
- RES25th of 45220
- Block1
- DP cost435th of 44634
- Redeploy70s
- Attack interval425th of 4552.9s
At Elite 2, level 90, before trust, potentials and modules. Each bar is measured against the highest value in the Arknights roster, and the place is out of every character with that stat, lowest first for DP cost, Redeploy and Attack interval.
By promotion
- Elite 0 Lv. 1HP: 822ATK: 387DEF: 52RES: 10Block: 1DP: 31Redeploy: 70Interval: 2.9
- Elite 0 Lv. 50HP: 1142ATK: 546DEF: 80RES: 10Block: 1DP: 31Redeploy: 70Interval: 2.9
- Elite 1 Lv. 80HP: 1428ATK: 700DEF: 110RES: 15Block: 1DP: 34Redeploy: 70Interval: 2.9
- Elite 2 Lv. 90HP: 1831ATK: 834DEF: 132RES: 20Block: 1DP: 34Redeploy: 70Interval: 2.9
Base values before trust, potentials and modules. Full trust adds ATK +105.
Trait
- Deals AOE Arts damage
Skills
3
ATK Up γ
Manual trigger · Auto recovery · Unlocks at Elite 0LevelATK +100%
- SP cost
- 30
- Initial SP
- 15
- Duration
- 30s

Lock of Shattered Time
Manual trigger · Auto recovery · Unlocks at Elite 1LevelStuns all enemies within Attack Range and deals 140% ATK as Arts damage to them every second
- SP cost
- 50
- Initial SP
- 30
- Duration
- 7s

Key of Chronology
Manual trigger · Auto recovery · Unlocks at Elite 2LevelAttack Range increases, attacks turn into ripples that spread outward, ATK +170%, increases the effect of the second talent to 3, and attacks knock targets back slightly
- SP cost
- 110
- Initial SP
- 80
- Duration
- 27s
Talents
2Skill Aura - Caster
- Elite 1
- When deployed, increases the SP recovery rate of all Casters by +0.2/second (only the highest effect of this type takes place)
- Elite 2
- When deployed, increases the SP recovery rate of all Casters by +0.4/second (only the highest effect of this type takes place)
Subjective Time Dilation
- Elite 2
- Slows the movement speed of enemies within this unit's attack range by 15%
- Elite 2 · Potential 5
- Slows the movement speed of enemies within this unit's attack range by 18%(+3%)
Potentials
- Potential 2
- DP Cost -1
- Potential 3
- Redeployment Time -4 sec
- Potential 4
- ATK +34
- Potential 5
- Improves Second Talent
- Potential 6
- DP Cost -1
Modules
2
Veteran Legatus' Customized Cloak (SPC-X)
Unlocks at Elite 2 Lv. 60StageStatsTraitTalent- Stage 1Stats: HP +120, ATK +55Trait: Attack Range expands
- Stage 2Stats: HP +165, ATK +68Trait: Attack Range expandsTalent: When deployed, increases the SP recovery rate of all Casters by +0.5/second, while own SP recovery rate increases by +0.7/second (only the highest effect of this type will be applied)
- Stage 3Stats: HP +190, ATK +80Trait: Attack Range expandsTalent: When deployed, increases the SP recovery rate of all Casters by +0.6/second, while own SP recovery rate increases by +0.9/second (only the highest effect of this type will be applied)
To unlock
- During battle, have your own Mostima use Key of Chronology a total of 5 times
- Clear Darknights Memoir DM-3 with a 3-star rating; You must deploy your own Mostima and have her defeat at least 3 Sarkaz Lancers
Module record
'Pasha, Your Excellency, this is the fifth story I've told for you. I hope it was to your satisfaction?'
In the resplendent palace of Sargon, a blue-haired Messenger, dressed in attire markedly different from those around her, stands at the foot of the steps, bowing respectfully toward the Pasha seated on his throne.
On the high platform, the richly dressed Pasha gestures to his attendant, whispering something to him. The attendant's face briefly shows a hint of surprise, then he steps forward to loudly announce the Pasha's decree, 'Messenger, my lord had never heard of such ruins hidden within the Black Flow, nor of the history buried within Victoria's ancient battlefields. Your stories have greatly pleased him, and he is willing to forge a friendship with Yvangelista XI from afar.'
'Thank you very much.' The blue-haired Messenger gives a polite and confident Sargonian court bow and begins to turn to leave. But the attendant speaks again, 'Don't be in such a hurry, Messenger. My lord has one more question for you.'
'Please, go ahead.'
'My lord wishes to ask if you would stay and tell him the remaining nine hundred and ninety-five stories?'
'Does... His Excellency the Pasha mean that he wishes for me to relinquish my role as a Messenger, and remain by his side?'
'Precisely. My lord offers you wealth and luxury here, in exchange for sharing with him all your enchanting stories.'
The blue-haired Messenger smiles. 'I thank His Excellency for his kindness, but I am accustomed to my life of freedom; such riches and luxury are not suited to me.'
The Pasha whispers a few more words to the attendant, who then steps forward again. 'You are already an outlier among the Sankta. Your kin will not accept you, and your homeland has no place for you. Why go to such lengths on their behalf?'
This time, the blue-haired Messenger pauses to think before answering, 'I don't journey for my kin, nor do I long for my homeland. In the beginning, it was an old friend who set me on my travels. Now, I travel out of curiosity for a certain story.'
'What kind of story?'
'An old man once told me a story before I left. It was a silly story about everyone eating ice cream together under the sun. But as I traveled, I began to see what was intriguing about it, and as I reflected more and more on it, I discovered even more stories.' The blue-haired Messenger gives another courtly bow. 'You should instead let me travel as far as possible, so that when I return, I may regale you with even more wondrous tales.'
The Pasha no longer tries to persuade her, only ordering that, whenever the blue-haired Messenger returned, the palace gates would always be open to her. As they walk out of the palace, her red-haired companion, who had been silently listening all along, finally can't hold back and asks, 'Did His Holiness really tell you a story like that?'
A smile appears at the corner of the blue-haired Messenger's mouth. 'What do you think?'

Home of 'Black Lock' and 'White Key' (SPC-Y)
Unlocks at Elite 2 Lv. 60StageStatsTraitTalent- Stage 1Stats: DP cost -8, ATK +51, ASPD +5Trait: Reduces Deployment Cost
- Stage 2Stats: DP cost -8, ATK +68, ASPD +6Trait: Reduces Deployment CostTalent: Slows the movement speed of enemies within this unit's attack range by 25%; Slows the movement speed of enemies outside this unit's attack range by 10% (unaffected by skill)
- Stage 3Stats: DP cost -8, ATK +82, ASPD +7Trait: Reduces Deployment CostTalent: Slows the movement speed of enemies within this unit's attack range by 30%; Slows the movement speed of enemies outside this unit's attack range by 18% (unaffected by skill)
To unlock
- Defeat a total of 100 enemies with Mostima (excluding Support Units)
- Clear Code of Brawl CB-5 with a 3-star rating; You must deploy your own Mostima, and have her defeat at least 8 enemies, including at least 1 Bully
Module record
When he was 10 years old, his homeland was laid waste by war, leaving him no choice but to flee. During his escape, he tumbled into a hole blown open by an explosion, and found the long dormant Lock and Key by accident.
When he was 20 years old, he became a Caster, and quickly earned the praise and respect of those around him, thanks to the Lock and Key's power.
When he was 30 years old, he had amassed great wealth and a reputation he could have only dreamt of. Yet, he had long since ceased to care about any of that. At some point, he began to talk to his staff day after day. Everyone thought he had gone insane.
When he was 40 years old, he suddenly disappeared from inside the palace one day, and no one knew where he'd gone. Rumors began to spread in certain parts of Kazdel that a madman would tell certain impossible predictions to anyone who passed him by in the barrenlands. For example, that a giant beast would soon lay waste to our nation and that the sky would one day tear in two and reveal its true face. Afterward, he would peddle his watches to whoever stopped to listen, and should they refuse, he would bring their time to a halt.
By the time he was 100, he no longer knew where he was, but that no longer held any meaning to him. He believed he was seeking the secrets behind time itself.
He had the Key, but where was the Lock?
He had the Lock, but where was the Key?
The past becomes the future, and the future shall have no secrets. Day after day, he talked to his own shadow, firmly believing that the truth was hidden within.
Until one day, footsteps echoed throughout, as three Sankta walked into the underground palace.
Base skills
2
Clue Search α
Reception Room · Elite 0When this Operator is assigned to the Reception Room, Clue search speed increases by 10%

Messenger - Penguin Logistics
Reception Room · Elite 2When this Operator is assigned to the Reception Room, Clue search speed increases by 10% and it's easier to obtain the clues of Penguin Logistics
Outfits
4
Elite 1
Default Outfit
Art by 幻象黑兔

Elite 2
Default Outfit
Art by 幻象黑兔

Spellbreaker
EPOQUE/V
Art by 幻象黑兔
Store

Ethereal Harmony
Ambience Synesthesia/VI
Art by 三目YYB
Store
Voice lines
38Show all 38 lines
- Appointed as Assistant
- Heheh, aren't you the lucky one, Doctor? I don't have any work for the day, so I wouldn't mind keeping you company for a bit.
- Talk 1
- The marketplaces of Lungmen, the suburbs of Ursus, the ancient ruins of Victoria... Doctor, these lands hold countless beautiful sights, but very few people ever slow down and take them all in.
- Talk 2
- Doctor, do you want to hear a story from my travels? In that case, I think we should get some fine tea cakes before we sit down. Otherwise, even the most captivating story will turn boring.
- Talk 3
- I've watched plenty of organizations rise and fall, but so far, Rhodes Island is the most interesting one I've seen. Will the epochs bend to your will, or finally swallow you whole...? I'm dying to find out.
- Talk after Promotion 1
- Doctor, I have a few ideas where we can get some good food at our next destination. Interested?
- Talk after Promotion 2
- Doctor, you seem to already know a thing or two about fallen angels. Unfortunately, I can't give you any more details than what you've got. Even if I shared everything else with you someday, that would stay my one secret.
- Talk after Trust Increase 1
- Doctor, you don't need to worry about maintaining a good relationship with me. Friends, family, and love... I've got nothing against them, but I don't need them either. Heh, not like that's going to stop you from trying, right? Well, I don't really mind, so give it your best shot.
- Talk after Trust Increase 2
- Hey, Doctor, I'm back from... Whoa, were you waiting for me here? You even prepared a whole table of snacks... Hehe, all right. How could I turn you down after a gesture like that? In return, I'll tell you about the fun I had on this last delivery run.
- Talk after Trust Increase 3
- ...I see now. The spark of joy I felt when I thought of having a friend like you wasn't fake after all. Scrap what I said before, Doctor. Maybe I do need a bit of warmth in my life.
- Idle
- Hehe... Sweet dreams, Doctor.
- Onboard
- Hey there, Doctor. I'm Mostima. You might've heard from Emperor that I'm not bound by the contract between Penguin Logistics and Rhodes Island, and can therefore act independently. Having that said, I'll probably be staying here anyway when I'm not busy. Sooo, I'll see you around.
- Watching Battle Record
- Well then, let's see how Rhodes Island fights.
- Promotion 1
- You know, Doctor, relying on me isn't a very wise decision.
- Promotion 2
- You really want to see me go all out, Doctor? Just for the record, I have to ask… Do I have to pay for the collateral damage I cause? No, right?
- Added to Squad
- OK.
- Appointed as Squad Leader
- Hmm... Sorry, but why don't we let everyone do their own thing?
- Depart
- Ah. I know this place. Let me lead the way.
- Begin Operation
- Get in, get out.
- Selecting Operator 1
- Uh-huh?
- Selecting Operator 2
- Heh heh…
- Deployment 1
- Nice weather today.
- Deployment 2
- Great view from here.
- In Battle 1
- Seventy percent-ish should do the trick.
- In Battle 2
- It's about time to wrap things up.
- In Battle 3
- I have nothing against you guys. It's just the story of our lives.
- In Battle 4
- I wonder what we should eat after this?
- 4-star Result
- Feels good. Guess I could use a thrill every now and then.
- 3-star Result
- Hm? I thought I missed a few, but I guess that's a job well done.
- Sub 3-star Result
- The results of a battle don't really matter to a Messenger. Just surviving is enough of a victory.
- Operation Failure
- Gotta admit, this 'teamwork' isn't really my thing.
- Assigned to Facility
- Mind if I go wander around?
- Tap
- Oh?
- Trust Tap
- Let's have a chat, Doctor.
- Title
- Arknights.
- New Year's blessing
- This day used to be like any other for me. Wouldn't stop long at any one place, wouldn't form any serious friendships, wouldn't have fun like everyone else. I never imagined I'd enjoy the holiday atmosphere here. I gotta admit, it isn't half bad. Happy New Year, Doctor, hope we all enjoy it.
- Greeting
- How's your day going, Doctor?
- Birthday
- So today's your birthday, Doctor. Happy birthday. Would you take an incredible story from my travels as a present? I guess not... alright, how about we take a trip together? I'll pick the scenery, you choose the time.
- Anniversary Celebration
- The more dangerous the place, the more enchanting the views get. Once you make it through every layer of danger, to finally stand in the eye of a Catastrophe, you're a part of the scenery yourself. In the end, where will you lead Rhodes Island, Doctor? I'm still dying to see.
Upgrade costs
Open in the plannerPromotion
- Elite 1
Caster Chip ×5
Polyketon ×7
Oriron ×4
LMD ×30,000 - Elite 2
Caster Dualchip ×4
Bipolar Nanoflake ×4
Grindstone Pentahydrate ×7
LMD ×180,000
Skill levels
- Lv. 2
Skill Summary - 1 ×5 - Lv. 3
Skill Summary - 1 ×5
Diketon ×6
Orirock ×4 - Lv. 4
Skill Summary - 2 ×8
Device ×3 - Lv. 5
Skill Summary - 2 ×8
Orirock Cube ×5
Device ×3 - Lv. 6
Skill Summary - 2 ×8
RMA70-12 ×4 - Lv. 7
Skill Summary - 3 ×8
Orirock Cluster ×5
Integrated Device ×4
Mastery: ATK Up γ
- M1
Skill Summary - 3 ×8
Orirock Concentration ×4
Grindstone ×7 - M2
Skill Summary - 3 ×12
Oriron Block ×4
Sugar Lump ×7 - M3
Skill Summary - 3 ×15
Bipolar Nanoflake ×6
Grindstone Pentahydrate ×5
Mastery: Lock of Shattered Time
- M1
Skill Summary - 3 ×8
Sugar Lump ×4
RMA70-12 ×5 - M2
Skill Summary - 3 ×12
Keton Colloid ×4
Polyester Lump ×7 - M3
Skill Summary - 3 ×15
Polymerization Preparation ×6
Grindstone Pentahydrate ×6
Mastery: Key of Chronology
- M1
Skill Summary - 3 ×8
Polyester Lump ×4
Orirock Cluster ×8 - M2
Skill Summary - 3 ×12
Optimized Device ×3
Oriron Block ×6 - M3
Skill Summary - 3 ×15
Polymerization Preparation ×6
Polyester Lump ×6
Module: Veteran Legatus' Customized Cloak (SPC-X)
- Stage 1
Module Data Block ×4
Polymerization Preparation ×2
LMD ×80,000 - Stage 2
Module Data Block ×4
Data Supplement Stick ×60
D32 Steel ×3
LMD ×100,000 - Stage 3
Module Data Block ×4
Data Supplement Instrument ×20
Bipolar Nanoflake ×4
LMD ×120,000
Module: Home of 'Black Lock' and 'White Key' (SPC-Y)
- Stage 1
Module Data Block ×4
Crystalline Electronic Unit ×2
LMD ×80,000 - Stage 2
Module Data Block ×4
Data Supplement Stick ×60
Polymerization Preparation ×3
LMD ×100,000 - Stage 3
Module Data Block ×4
Data Supplement Instrument ×20
Bipolar Nanoflake ×4
LMD ×120,000
How to get Mostima
Recruitment & Headhunting
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