Nature's Wrath XXG
Instant
When you play Nature's Wrath sacrifice X creatures. Each sacrificed creature deals damage equal to its power to target opponent.
I've always believed green could use a direct damage card. Nature's Wrath has the power of a good red spell, but keeps the feel of green. Aggro could attack all out and then play this sucker on the stack.

New Name: Gaea's Wrath