User blog comment:Flameflire/Ash's Future Pokemon/@comment-38149523-20191227121306/@comment-44688178-20191227142542

I mentioned thinking about this tough I honestly don't know

I hope he will get one of the 3 types he hasn't caught before - Fairy, Psychic and Ghost

Lucario would be a good fit for him.

Remember he caught Aipom on his Battle Frontier journey and Gligar in Sinnoh and they both got new evolutions in Gen 4 so it's not impossible just rare.