This is mostly fine, but I am going to have to stipulate that he will need an added Psychic typing, so much of what he does is associated with the Psychic typing in this game that I can't really justify him not having that.

Beyond that, I'd like to see a slightly higher limit on the buffs, I'd say he can apply 2 at first evolution, 4 at second, and all at final evolution. The other stacking mechanics are fine as-is.