"Diplomacy has solved nothing. Only bloodspill can end this now. Call forth the warbringer."
—Basandra, Battle Seraph

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Commander Masters

Commander Legends: Battle for Baldur's Gate

Commander Anthology

All creatures have double strike and attack each turn if able.

Commander 2011

If, during a player's declare attackers step, a creature is tapped, is affected by a spell or ability that says it can't attack, or hasn't been under that player's control continuously since the turn began (and doesn't have haste), then it doesn't attack. If there's a cost associated with having a creature attack, the player isn't forced to pay that cost, so it doesn't have to attack in that case either.