Exile a creature you control: Add X mana of any one color, where X is 1 plus the exiled creature's mana value. Spend this mana only to cast creature spells.
Whenever a nontoken creature enters, its controller creates a token that's a copy of that creature.
Whenever a nontoken creature leaves the battlefield, exile all tokens with the same name as that creature.
When this enchantment leaves the battlefield, exile all tokens created with this enchantment.