Once per turn when you make a melee attack against an enemy, hit or miss, your allies gain a +1 attack bonus against that enemy until the start of your next turn.
Invocation of War/Leadership: Increase the escalation die by 1.
The attack no longer has to be a melee attack, close and ranged attacks also work.
The bonus now applies against all enemies you attack; you no longer have to single out one foe if you use a spell that attacks multiple enemies.
Allies now also get a damage bonus against such enemies equal to double your Charisma modifier.