Zukan

Zukan is a villain introduced in the WW3 arc. He is played by Cor.

Information
Zukan is first introduced as the mouse who saved Eri and Bakugou from the Strikers during the simulation. His quirk is the same as the last person who touched their hand to his. He uses Shinsou's quirk to find information from the group before his "reveal" as a traitor. He was created to be an obvious villain from his meeting point.

He immediately clashes with Eren, who claims Zukan accidentally killed Eren's sister. However, under Shinsou's quirk, Zukan says it was on purpose. He is also revealed to be in love with Eren. This sparks Shinsou to refer to Zukan as "Yandere-kun" to annoy him.

Zukan attempts to kill Tokoyami in a fight, which prompts Dark Shadow (Calibris) to seek eventual revenge by hacking him to pieces. Tokoyami even brings his liver back to Mei. Despite this, he was not marked deceased on the character list, which hinted that he will be back.

Backstory
All that is currently known about Zukan's backstory is that he killed Eren's sister.