The adventre I remember that involved it was the CN/E quasi-deity PC Sunneson, servant of Tuoni, and rival LG demigod PC Thrin, seeking the (sword-dominated) merman who had the Sword of Kas through a wormhole into cyberpunk 21st century New York, battling street gangs and the Arasaka Corporation. This was a sequel to the Sword's previous appearance, where someone had tried to get rid of it by throwing it in the sea - hence the merman.