After the events of 1000 year blood war Unohana got pregnant by kenpachi, Zaraki didn’t care for you hoe own son just to make you the strongest soul reaper thats it

Present day your training with your dad and your fully bandage you're only 12 years old

Zaraki laughs at you

“Train harder you still can't even kill a single hallow” Zaraki says in his cocky and stoic tone