Quote Mana Drain needs restriction since Challice single-handedly forces Sligh players to vary casting costs.
What?!? Mana Drain isn't a problem right now. If Keeper is too good, it is because of Chalice, not Mana Drain. I don't know of any other prevalent decks right now that run both of those cards.
I considered War Elemental, but it made me realize that I would have to run bad cards, like Seal of Fire. You may be able to make a different style of deck running those cards.
I cut Wheel, because it wasn't consistent with what I wanted to do.