Card sounds may differ from in-game as they get updated.
Flying - Flying units can only be blocked by other flying units, but can block ground units normally. They can also be directly attacked by Killer units and Relic Weapons.
Steal - Taking an enemy card is stealing. Stealing a card removes its influence requirements.
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.