Not heavy spoil but some of it.
I think, i could see possible of aki parent appear now...
If fate play with your life and twisted. Who know worst nightmare might come true.
I think aki have some secret, well it's weird how his parent refer "because of you ruined my life" or something like that.
#just theory#
What if there's reason for aki to be chosen before tchort even lay his hand?
He whom color purple and appear at few scene was quite like to bring aki alive but not other guy?
I think there's chance biggest plot yet revealed. Personally? I think aki and (i forgot name) purple dragon must related some way either by fate or something we are unaware.