Good mastery tree, but distortion is probably one of the greatest spells ever. I always max first even though sigil is primary nuke. Distortion maxed with your item build (Mejas early, like that idea a lot) means more AoE damage sooner. This allows for faster lane pushes in clearing creeps and hopefully getting the gold required to become dominant. Another sidenote, Rylai's wouldn't be my personal choice, yes it gives that bonus HP but it is merely a crutch of players who can't play smart. Getting a pure AP item with magic pen or another perk is usually my preference. Overall though, good build. 4/5