Smeargle gets the ability to copy base stats with Sketch.

How would that even work?

Huh?

que

You already do that. Copies nature, level, and species base, as well as any enumerated stat buffs or debuffs. Everything but IVs. It even gives you all 4 of their moves.

It's called Transform.

Copies the base stats of Mega Rayquaza, has the best ability in the game (Moody), can learn every move. Easily the best mon.