Duality is a Dungeon that was added to Destiny 2 in the Season of the Haunted. It revolves around Eris Morn sending Guardians into the mindscape of Calus, only to find it a dangerous schism overrun with his Nightmares. Guardians must fight through the emperor's shame-ridden fractured consciousness to steal knowledge from the deepest parts of his mind.
We will help you get weapons and armor, as well as an exotic sword Heartshadow