Rally To War

Rally — Whenever Rally To War or another Ally
enters the battlefield under your control, Amass
Soldiers 1.
Whenever an Army you control attacks, put a battle counter on Rally To War.

As long as Rally To War has two or more battle
counters on it, creatures you control have vigilance.

As long as Rally To War has four or more battle counters on it, creatures you control get +2/+1.