Card sounds may differ from in-game as they get updated.
Ambush - An ambush unit can be played at the end of the enemy player's turn, or any time they are attacking you. If you played against a Killer or Relic Weapon attack, an Ambush unit will jump in the way to block that attack.
Amplify - Cards with Amplify will let you repeat their effect when played if you have the extra power specified by the Amplify number. It is optional and may be used more than once.