Celestial Fury

Celestial Fury is a katana +3 in terms of the level of enchantment. It inflicts 1d10 +3 points of damage and it stuns opponents when they can't make make a save vs. spells (Booming thunder) and there is a 5% chance this weapon will inflict +20 points of electrical damage (Shocking blow). The wielder of the blade may also use Blindness and Lightning Strike once per day when wielding the katana. It has a +3 thaco bonus, a speed factor of 1 and it weighs 3 lbs.

This item appears in Baldur's Gate II: Shadows of Amn. It can be found in Guarded compound of the Athkatla Temple District. When one enters the house, the owners will see this as trespassing and the proud mages try to lure the party deeper into the house. At the second floor, the mages will fight the party and one of them drops the weapon.

In-game description
"Katana +3: To enchant a katana is no simple process. Unlike conventional weapons, the katana is already a near-perfect fighting sword. To improve it usually requires a sacrifice, perhaps a dying samurai might beg a Wu Jen to infuse his fighting spirit into the spirit of the katana. The wielder of an enchanted katana, such as this one, must respect the customs of Kara-Tur and of the samurai who once carried this blade into battle. Not doing so could drastically change one's luck for the worse."