As soon as the Will-o'-Wisp's manifestation completed, Liora ordered an attack without preamble or threatening posture that would telegraph any intention…
The spirit simply disappeared from its initial position and reappeared directly above the mantis, an enormous mass of purple fire descending like an incandescent avalanche.
It was the signature danger of the Will-o'-Wisp that made it particularly terrifying to face. Practically instantaneous teleportation that converted any distance on the battlefield into something irrelevant.
The spirit could be on one side of the field one moment and literally on top of an opponent the next with almost no visible transition between states.
