I'll save you.. I promise

This has been in my head for so fricking long. Have some soft, good parent Overhaul.

After Kai is shown that Eri will be staying with him, he feels a need to protect her at all costs. He brushes it off up until the Hassaikai boss, Eri's grandfather, forces him to make incisions in her arms so that he can take her quirk cells to make quirk destroying bullets that he realises the need to protect her.. was a warning from his own mind that his boss doesn't care she is part of his blood.
In result of this... Kai is willing to do anything that will get Eri out of the Shie Hassaikai and to safety with the heroes...

...even if it means he gets seen as a villain by the heroes in return.

This is also a trans overhaul book because I read a theory about him being trans cause the bottom lashes of his eyes don't fit his aesthetic.

I do not own the characters of My Hero Academia. All credits of characters go to Horikoshi.