even if he can not use the technique yet at least he would not have worry in the future

why doesn't he leave a kunai behind to teleport to in an emergency

that's if you include story\movie type games as a movie

final fantasy 7 and 8 save aerith for harem then use 8 as a holiday bonding time

plus 1

DMWG so he can go with his friend to make him stronger and have as an ally also with the time you put out they can learn alchemy and smithing also pick up techniques. With his training with whis he has god qi which should be similar to heavenly energies or divinity so cultivating should help him better control and improve his qi. I assume there also a lot more you could do but these are some suggestions you could use to justify a big increase of power for MC and his friend and allow for some acceptable time skips considering you have over three million years to cover

Harry Potter world to learn mind arts to get control of there oozaru form