No Mutants Allowed

Mew, Celeby, Manaphy, Jirachi, Victini, Diancie, Magearna and Marshadow will always be event exclusive.

And Keldeo, Meloetta, Hoopa and Genesect too.
USUM is probably gonna have a system like Hoopa's rings in ORAS but contextualized as traveling to other dimensions through Ultra Space. WOuld be cool to see the Legendaries getting their own Dungeons just like UBs will have.

The "cute" 600 BST event mons (Mew, Celebi and so forth) will never be wild pokemon to catch. The only event mon that was made obtainable through ingame means was Deoxys and that's a very rare exception.

I was just going through ORAS again to get spare Legendaries with good natures but it seem like I will be able to just catch them in USUM.

I really hope we get some event mons put into the wild. I don't expect it to happen, but I want it to happen.

@Walpknut I've actually never noticed what natures do. I always assumed they were just flavor text. What do natures even do?

All natures boost the growth of one stat and hamper the growth of another. THere are 5 neutral natures that don't affect any stat.
https://bulbapedia.bulbagarden.net/wiki/Nature#List_of_Natures

Also there are some Berries that offer a lot of healing when consumed in battle that will confuse your pokemon if their nature makes it so they dislike the taste.

Ah. Alright, that's interesting. I've never really bothered with the in-depth mechanics like natures or EVs/IVs.

NERD ALERT! NERD ALERT! NERD ALERT! ...

And people say Pokemon is not an rpg....

Pokemon is really good at being both accessible and in-depth. I just wish there was a). a way to see your EVs and IVs and b). a slightly easier difficulty and a much harder difficulty.

Uhmmm there is a way to see EVs and IVs.