Card sounds may differ from in-game as they get updated.
Killer - A unit with Killer can make one special attack directly against an enemy unit. This can be done the turn it's played, and can target any unit, regardless of Flying, Aegis, or other special abilities.
Summon - Does something when played
Stun - Exhaust a unit. It can't attack or block next turn.
Plunder - You may choose a card in your hand to transform. If the card you chose was power, it becomes a Treasure Trove. If the card you chose was not power, it becomes a Sigil of its factions.
Imbue - When you play a unit with Imbue, you may stun one of your other units and keep it stunned. As long as it’s stunned, this unit gets its strength and health.