Card sounds may differ from in-game as they get updated.
Aegis - Aegis protects a unit or player from one enemy spell or effect. It doesn't block friendly effects, nor does it stop battle damage from Killer attacks, Relic Weapons, or normal attack and blocking.
Double Damage - Deals double damage.
Lifesteal - Units and spells with Lifesteal give you health when they deal damage, healing you equal to the damage dealt.
Overwhelm - A unit or spell with Overwhelm will deal any excess damage to your opponent on your turn (does not work while blocking).
Decay - When this deals damage to unit or relic weapon, that card’s strength and health (or armor) are permanently reduced by that much.