I would hands down play that dungeon, I reckon it'll be in the Cosmodrone between the Forgotten Shore and King's Watch that is meant as a Endgame dungeon for everyone. Loot should be: - Outbreak Perfected (Always Drop first time, only once) with a Exotic quest on the side to give you the catalyst. - 1 Exotic Weapon that is either Siva Themed (Most likely this) or Iron Banner Themed, or perhaps.... A legend, a story long foretold. - The Wolf's Horn, Legendary Rocket Launcher (Solar) with a new intrinsic, but without need to aim for tracking and ADS for more intense tracking. Pinnacle version will have a perk called "Cluster Pack Rounds" that act nerfed Cluster Bombs, but can Track and deal more damage to Rank and File units. Will contain lore. Either drops in Iron Banner or Dungeon. - Siva based weapons and armor - Lord Saladin most likely will talk to you if Iron Banner is active, if not then it'll be Tyra Karn that will be talking to you (A Cryptarch that once resided at the Iron Temple, then the Farm until the eventual vaulting which removed the Farm, a social space in the EDZ). - Selling point to have people focus on it: a new 150 HC appearance, yes you heard me right. But the Aim Assist needs to be the same as Sunshot, no doubt about that. Finally, how one unlocks this dungeon? Completing a quest in Iron Banner, that does mean playing the gamemode, but that's about it literally then it will shift to PvE with using those Iron Banner weapons a bit. With lore can come with more clues to find the true treasure beyond time quite itself. Overall, I am somewhat conflicted to think of making this a DLC concept since well... It's in the Cosmodrone most likely (a nerfed version of the Cosmodrone to be specific with lacking an area(s) related to Devil's lair Strike in D1), but I have no control of that except Bungie ofc. There might be a reason like how Zavala said some part of the Cosmodrone is... Contained? Just with how little the loot is after Beyond Light and the patch to add more loot is still, lacking for some reason. Especially with World Loot and themed loot for other planets with how empty in liveliness they are I would assume.