So after playing Sun/Moon for a while, I keep getting the feeling that there's a lot of easter eggs and references to the anime or past games that are lost on me..

For example those two people that keep bothering me about the Zygarde cube, Sina and Dexo, Are they from a prior game or the anime show or something?

What about those two guys that meet you at the battle island place? Literally their names are Red and Blu... Another reference?

What about the guy from the Pokemon Island mini game? it seems like the game is referencing that he has been seen before?

Lastly, what about the "artsy" girl? I think she was an Island Kahuna...but she's really passive? I forget her name. She has like a painters/artist look about her...

What other easter eggs and "cameo" characters are around in Sun/Moon and who are these guys?