Also consider that once you declare your creatures as attackers, you can safely play instant damage spells like Fault Line and Comet Storm to clear the way
Mill is a very popular archetype in EDH, and The Water CrystalThe Water Crystal fits perfectly there...And that's probably its only home
Yes, The Crystals from Final Fantasy cost double to cast, but they do have some added upside: each has a static effect and an activated ability to use late game
(Each in the mana costs of permanents you control counts toward your devotion to black.) Creature - Zombie Color tag templates(None) Harsh Mentor Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, this creature deals 2 damage to that player
Though its not super competitive, its a solid green commander that gets out of hand in a hurry