From Archon Arcana - The KeyForge Wiki
The active player can resolve an ”Action:“ ability during their turn if it is on a ready card they control that belongs to the active house. Using a card with an “Action:” ability causes the card to become exhausted.
If a card has multiple “Action:” and/or “Omni:” abilities, only one of them can be resolved each time the card is used.
Related Topics: Omni, Using Artifacts, Using Creatures
—KeyForge Master Rulebook v17 April 2023