Wouldn't it funny if gamefreak were looking at this thread right now looking for ideas?
If they are, they'd better have seen that Fighting Eeveelution and the Dunsparce evo a couple dozen pages back...!
Oh, and and give some buffs to Poison, Ice, and Grass types too, huh? *ahem* Anyway...
Here's an idea that's been on my mind lately and I think has a lot of potential: Signature moves. What got me started on this was my old Swampert from RSE... he was the ONLY Pokemon to learn Muddy Water, it was his signature attack, so I kept it over Surf... only to later realize Surf is nearly always superior due to higher accuracy.
But what if every Pokemon in the coming generation had a new trait: it's own Signature Move? How I see this being implemented is the signature move would have different or added effects, varying on the specific move. For example:
Swampert's signature move is Muddy Water. Muddy Water is usually 95BP, 85ACC... but if it's a Signature move, it instead has 95BP, 95ACC.
Blaziken would have Blaze Kick, which instead of 85BP, 90ACC would be 95BP, 95ACC.
Scyther's signature move could be Aerial Ace, which gains a high Crit Ratio if it's a signature move.
Obviously, there'd have to be care given to things like Salamence gaining a signature Outrage with 130BP, but I think this would be applied more to rare, less commonly used moves that fit flavor of each Pokemon. It seems like it would open up new opportunities for some Pokemon... what are your thoughts?