Pokesona/oc of mine. Smeargle always fitting for an artist.
I think this ref is self-explanatory enough, but I guess I can detail a few things.

His moves are performed in a particular way, involving his tail and painting your doom. Spirit Shackle activates when he paints the surface where your shadow is, (or inversely, if your shadow crosses a painted surface) trapping you in place.
For Diamond Storm he flicks his brushtail, the drops of paint turning into large speeding chunks of gemstone, Ow!
Spacial Rend being the most dangerous, he swings his brushtail in the air, erasing the space there. Can be used to destroy things in his way or launched forward as a projectile of nothingness.

His father was the one to come up with the usage of transform learned through sketch, since Zoroark pride themselves on their skill to disguise as others. And although Campbell does not share his father's aspirations for domination, the climb to greatness feels too good to stop.