If an Activated Ability has a condition on “using” or “playing” it, that condition must be true in order to activate the ability in question. Example: Ultrasoft Poro reads “[E]: Play two 1 [M] Bird unit tokens with [Deflect]. Use this ability only while I'm at a battlefield.” In order to activate the ability, Ultrasoft Poro must be located at a battlefield.
§ 377.2.b Core Rules PDF (officieel)
§ 377 Activated Abilities are repeatable effects with a cost. They follow a process of going onto the chain and resolving, similar to Playing a Card. See rule 349. Playing Cards for more information.
§ 377.2 Card text will refer to activating Activated Abilities with the word “use” or “play.”
