Challenge of the Elders

Challenge of the Elders is the newest difficulty of Prison of Elders added with the April Update. Instead of the usual five rounds (four waves of regular enemies plus a boss round), this game mode will three rounds of bosses with special abilities. These bosses rotate each week:


 * Pilot Servitor—the Pilot Servitor can now teleport around the arena and will fire a barrage of bouncing Shock Grenades.


 * Wretched Knight—the Wretched Knight now has the ability to summon floating Taken mines that will spawn in the outskirts of the arena. This is supposedly to get players to engage him in a more direct manner.


 * Overmind Minotaur—the Overmind Minotaur is capable of capturing Guardians in detainment bubbles. They must be quickly destroyed or anyone inside will be killed via suppression field.


 * Val Aru'un—Val Aru'un has an invulnerable elemental shield that can only be disabled if the corresponding Psion Flayer in the arena is killed.


 * Keksis, the Betrayed—Keksis will gain the ability to summon an explosive that will suppress Guardians of their Super, grenade, and melee abilities if it goes off. This can be countered by running through it.


 * Sylok, the Defiled—Sylok's ability to fire lingering Solar traps is greatly enhanced. Once the jets land, they will create a much larger flame spot that will last much longer.


 * Seditious Mind—the Seditious Mind will summon a blight bomb overhead. Before the bomb detonates, it will create a circle of fire that will periodically damage any Guardians trapped inside, and when the bomb explodes, it will deal massive damage and can kill a Guardian who hasn't already gotten out of the way.


 * Noru'usk, Servant of Oryx—fires Axion Darts like ordinary Taken Centurions do.

After the final round, you will not be able to enter the Crystal Barrow, as you will get a guaranteed reward from Variks at the Vestian Outpost if you reach the necessary score for your Elder's Sigil.