Keldon Battlewagon

Trample (If this creature would deal enough combat damage to its blockers to destroy them, you may have it deal the rest of its damage to defending player.)
Keldon Battlewagon can't block.
When Keldon Battlewagon attacks, sacrifice it at end of combat.
Tap an untapped creature you control: Keldon Battlewagon gets +X/+0 until end of turn, where X is the tapped creature's power.