yeah, at the end of arc 10, it seems that there is an antagonist that is rebirthing, too. tbh, i suspect that MC is now living through all his previous lives that he doesn't remember or smth.
arc 10 gives us some hints and makes me think that all the lives MC really lived through, but how ML is part of this (after all, MC and ML never really got together in the supposed previous timelines...), i don't know. and the antagonist threw me off, omg, what? soooo interesting!
sadly i have exams in the near future, so won't have time to read >.<