Alpha
From Archon Arcana - The KeyForge Wiki
When a card has the alpha keyword, it can only be played if you have not played, used, or discarded any other cards during the current step of your turn.
If a card would gain alpha as it enters play, that card can only be played if you have not played, used, or discarded any other cards during the current step of your turn.
—KeyForge Master Rulebook v17.3 March 2024