Celestial Prism Celestial Prism is a classic, straightforward mana filter
Not only does it allow its owner to win the game if their deck is reduced to zero cards (completely reversing the games rules!), but it also allows the player to remove cards from their deck when dealing damage to their opponents Life
I feel that, in general, Think Twice is overplayed
To make up for it, this card has Learn on it
Stitch can quest for two, and has decent attack and defense, particularly for a three or four cost card
Illuminor SzerasIlluminor Szeras sacrifices creatures to make mana, which can help you get to some of the awesome high cost cards in the deck a bit sooner, but may stumble if you can't find card advantage to make up for the things you're sacrificing and ramping out