Right now what I'm thinking is...
1) You have to have some way to make use of its instant speed. Yes, being an instant is inherently more useful than being a sorcery, but if you end your turn with three cards in hand and four mana open, it's pretty telling what you're planning on doing. Punishing Maverick? Flash creatures? Some way to make its instant status feel natural.
2) It's mana heavy. I have an unorthodox idea that I'm going to keep to myself for now just so that the thread doesn't get cluttered by people spouting bullshittery.

