Well, in the
beginning, Hiroto was looking for someone to at least nullify his stepsister's insta death ability so he would have a better chance in dealing with her.
If Kaizuki can block the stepsister's reflection ability, that would be great, but if that were the case, I think Kaizuki would've have been viewed as a big threat to the stepsister instead of Okitsu.
Speaking of Okitsu, damn is she vulnerable. Looks she's going to get recruited no matter what. Hopefully, Mayu doesn't have any brainwashing tools at hand...
Thanks for the update, Heat.