Your weapons Spellcraft for free.
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.
Spellcraft - When you play a weapon with Spellcraft, you may spend power to create and play the listed spell.