I probably already know wat his weakness will be I think.
Hasuki's new path will hold the ultimate weapon against Turkish
I also think his reasoning for this move will be incredibly petty and personal. Who wants to bet he will go the "no boy is good enough for my daughter"?
And than Romio's mom appears, or Ragdoll turns out to be real head of family, or father is just grown-up male version of Leon, or friendship and love overcomes evil, doesn't really matter cause this final arc is already shit and nothing will redeem it.