I think Wrenn and Six also plays a big role in the playability of Quicken, as in order for it do what youre hoping for you need to be hitting your 5th land drop
If youre looking for one that has actually received its own creature card, that award goes to Emrakul
Legendary Creature - Skeleton Rogue Color tag templates(None) Valentin, Dean of the Vein Menace, lifelink If a nontoken creature an opponent controls would die, exile it instead
Magda will drop either a powerful Artifact or Dragon into play for the low cost of five Treasures
Skaab Ruinator isn't a bad card as we're certainly likely to have cards in the graveyard due to manifest dread, but we're not likely to have that many early on, risking Skaab Ruinator being a dead card if it's drawn in your opening hand
Don't waste a dragon other then that