Aggravated Assault + Bear Umbra

Prerequisites

You control an additional creature. An additional creature does not have summoning sickness. Bear Umbra attached to that additional creature you control. You control lands that can tap to produce at least {3}{R}{R}. An opponent is unable to block and kill creatures you control.

Steps

1. Declare enchanted creature as attacker.
2. Bear Umbra triggers, untapping all lands you control.
3. Proceed to your next main phase.
4. Activate Aggravated Assault by paying {3}{R}{R}, untapping all creatures you control and getting an additional combat and main phase after this one.
5. Repeat.