Considered adding a Nezumi Shortfang, in place of the ravenous rats?

You may get more than 1 discard out of them, and they become The Rack once there are no more cards to burn, so they're use doesn't disappear.

hah didn't think about that, I'll try out 2. Thanks!

Master of the Feast would give you a beefy 5/5 Flyer on the cheap, and it would ensure that your opponent actually has something to discard on your turn. Discard is sorcery-heavy, so many opponents will just try to use things as they draw them, instead of waiting for you to make them throw it away.

that's an interesting idea Buckminsterfullerene. I was trying to go creatureless because of the Ensnaring Bridge, so I don't know yet. Thanks for the idea though!