Mastery 8: +2/+2.
Card sounds may differ from in-game as they get updated.
Berserk - Units with Berserk can make a special double attack one time: If it survives the first round of battle, it will attack again. This can only be used once, and gives the unit Reckless.
Mastery - All damage dealt by units with Mastery count towards its Mastery ability. When its Mastery number is met, it uses its Mastery ability.