Why is Grimley in Alola and other trainers who could appear in Ultra Sun and Ultra Moon

Hey, guys!
Have you wondered why Grimsley of the Unova Elite 4 is in Alola? I have a theory that he might be a member of the royal family of Alola. My biggest evidence for this is that the royal family of Alola is no more and Grimsley is a member of a distinguished family that fell into ruin. What do you think?

Also while on the topic of trainers from other regions, what characters do you think will make an appearence in Ultra Sun and Ultra Moon?

Again, my money is on Grimsley.

Heya, this thread belongs better over in our Ultra Sun/Ultra Moon section, I'll move it over there so you can get better input on your theory.

He is just there for the sake of being there. I see no particular reason to why he is in the game. Same applies to other guest appearances. We might get a few more in USUM.

Kinda seems out of place as does Colress. Makes you wonder what they have planned for them since it seems quite odd for them just to be there for the Battle Tree. They seem to fit into the storyline so I'd be interested to see whether they have some sort of prominent role in USM.

Given Solgaleo/Lunala's new forms, despite them clearly not being fusions in the way Black/White Kyurem are, I think Colress' appearance in SM was either foreshadowing for that, or blatant setup bait for USUM. I doubt they'd draw too many similarities, and it seems unlikely that if Colress was in USUM he'd have the same antagonistic role.

As for Grimsley...god knows. xD

I can't see what Grimsley's appearance would hint towards, but I think it's fair to say Colress may have had a part in those new forms of Solgaleo and Lunala, especially when you consider the role he had in B2/W2.

I do not think Corless has anything to do with the new forms we seen. He and Grimsley are just placed in the game with no particular reason. Characters like Cynthia didn't need to be unova and yet she was. Colress won't have an important role in USUM and neither would Grimsley.

I agree with the two posts above me regarding Colress, but I feel like GF wouldn't add a rather obscure character such as Grimsley for no reason. Perhaps he is an Alolan native who got famous elsewhere returning to his home to fill a spot in the elite four?