The Sword of Chaos is a powerful greatsword that you can get in by defeating one of the strongest servants of Bhaal in the game. This Very Rare magic item can cleave through your enemies and recover some of your Hit Points when you hit hostile creatures. Although there are limitations to which characters can use this weapon, the Sword of Chaos is an excellent weapon.
Since the Sword of Chaos is classified as a Greatsword, only characters who have proficiency with martial weapons can reliably use this item. Make sure to check someone's class features if you are wondering if they can use the Sword or not. The best companions in who might be the most qualified to wield the sword might be Karlach or Lae'Zel if your custom character is designed for something other than close combat.
The Sword of Chaos can be found in Act 3 as loot from killing Sarevok of the Bhaalist Murder Tribunal within the Lower City. Solving the Open Hand Temple murders will lead you to discover a group of cultists worshiping Bhall, the god of murder, underneath the city. The side quest related to the murders in Baldur's Gate will reveal certain culprits tied to this hidden society of killers.
Pursuing enough clues should lead you to Candulhallow's Tombstones or an area near Elfsong Tavern on your map. Evidence found from the Open Hand temple murders will let your party use a specific password to enter the cult's lair below the city through a secret passage. From here, you will meet the NPC Sarevok or the leader of the Bhaal cultists, who have been causing so much terror.
While you can make decisions that convince the cult you are on their side, the Sword of Chaos is Sarevok's and Sarevok's alone unless you kill him. This enemy is surrounded by allies,
Read more on screenrant.com