The Mace 'Taratol' (3d4) (+12,+12)
*Slays* dragons. Branded with lightning. Provides immunity to lightning. Cannot be harmed by acid, electricity, fire, cold.
When activated, it hastens you for d20+20 turns. Takes 101 to 200 turns to recharge.
Min Level 20, Max Level 100, Generation chance 7, 20.0 lbs

(Angband 3.1.2v2)