Where exactly are you seeing this? There's nothing under the ability details that says anything about needing to have targets be in combat with you. It specifically says "Deals unaspected damage to all nearby enemies with a potency of 300." Just tested it, that statement isn't correct. Stood right under a level 31 Buffalo in Costa Del Sol where I happen to be right now, flipped to Cleric Stance and hit Assize, and it instantly did 1798 damage to it and killed it in one hit. It wasn't in combat with me or even attacking me at all.
