Kalvin (Kor. 칼빈) was a member of the assassination squad working for Dr. Crombel. He was sent to Korea along with Mark to aid Yuri in collecting the remaining data of Frankenstein's research.


Kalvin appeared to be a boy of around 15 years of age. He had long, spiky black hair with the portion behind his ears being dyed yellow. He had dark circles under his light grey eyes, implying his work was exhausting.


He was shown to be respectful towards Mark and Yuri. Though he had a pretty serious attitude when it came to his work. According to Yuri, Kalvin had a taste for women older than him. Kalvin liked to trick his opponents. This attitude was shown when he tricked M-21, Takeo and Regis into consuming his poison in exchange for the antidote to save the children but later didn't fulfill the exchange. Even after his death, the antidote taken from him proved to be a fake.  

Plot Overview

Volume 5

Traitorous Clan Leader Arc

Destroyed School

Kalvin accompanied Mark and Yuri on a mission assigned to them by Dr. Crombel to procure the remaining data from Frankenstein's residence. Mark comes up with a plan for the data to be brought to them rather than going for it themselves. They kidnap the children and Kalvin administered poison to them.
They waited on the school premises where M-21 arrives, however, the RK team manages to rescue the children as well as protect the data from the assassins. The two teams collide on the school grounds and Kalvin revealed that he'd poisoned the children. An enraged M-21 attacks them, later joined by Regis and Takeo. Kalvin found himself confronted by Regis. He got pushed back repeatedly and threatened Regis, showing him the vial of antidote which he would destroy should Regis continue attacking. Kalvin repeated this for everyone to hear and gives Regis, M-21 and Takeo small pellets that he demands they take if they want the antidote. They fall prey to his trick and Kalvin laughed while revealing that he had actually given them lumps of poison and refused to give the antidote to Regis as promised. Regis' weak attacks are of no use and Kalvin gloated in triumph.
However, the sudden arrival of Rael turns the tables. Kalvin, not knowing who he is, tried to attack him but the instant that his attack hit the ground, Rael appeared behind him and stabbed a hole in Kalvin with his bare hand. Yuri and Mark flee to save themselves while Kalvin is left behind to face Rael's wrath. The convict tried in desperation to survive and even threatened to destroy the antidote, however, Rael shows no interest in the antidote. Kalvin was then killed by Rael who procured the antidote as well.


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Powers & Abilities

Kalvin was skilled at assassination and belonged to the assassination squad.

Poison Manipulation

Kalvin specialized in preparing poisons and antidotes. It is unknown whether he carried the poison, or if he generated the poison. He generally used green, acid-like poison during battle to overcome his opponents. His poison was quite strong and corrosive enough to melt a wall.



Rai's Group Rai · Frankenstein · M-21 · Tao · Takeo · Shinwoo · Ik-Han · Yuna · Suyi
Nobles Raskreia · The Previous Lord · Gejutel · Karias · Krasis · Kei · Ludis · Rael · Ragar · Rajak · Regis · Rozaria · Seira · Claudia · Edian · Gradeus · Ignes · Lagus · Roctis · Urokai · Zarga
Werewolves Muzaka · Maduke · Lunark · Kentas · Ashlyn · Garda · Dorant · Juraki · Grui · Gaitan· Kuharu · Mount · Drakon · Kaiyo · Gayare · Mirai · Urne · Uzhir · Gorma · Krano · Braang · Zaiga · Gaura · Gotaru · Bashum
Union Elders 1st Elder · Maduke · 3rd Elder · Roctis ·Lunark · Urokai · Zarga · 8th Elder · 9th Elder · Rostere · Muar · 12th Elder · Dr. Crombel
Union Agents & Members Dr. Aris · Bonerre · Geo · Hammer · Haydn · Ignes · Infected · Jake · Kalvin · Ked · Krantz · Lutai · Mark · Mary · Rodin · Shark · Taze · Yuizi · Yuri
KSA Lim Taesik · Sangeen · Yonsu
Others M-24
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