Interact

A unit 'interacts' with the realm if it does any of the following things: Strikes (even if the strike is replaced with another effect) Casts a spell Activates a special ability Note that only activated abilities can be activated. Triggered abilities and passive abilities aren't activated.

Note that a 'special ability' is different from a 'basic ability'. Deal damage (even if the damage is prevented) If a unit's damage-dealing triggered ability (e.g. Infernal Legion, Colicky Dragonettes, Redbreast Robin, etc.) doesn't actually hit anything, it has not interacted with the realm. If it hit something (whether or not damage was prevented), then it has interacted.