Understand The Arena
Upon entering the arena, you’ll notice that the Wretched Knight stands in the center of the room guarded by ogres, wizards, acolytes, and thrall. At all times, you must maintain an awareness of these additional enemies, as they will continuously respawn until battle is finished.
While you will absolutely need to fight these enemies in order to survive throughout the battle, your primary strategy should be to deal heavy damage on the Wretched Knight as quickly as you possibly can. This does not need to be a long battle. The Wretched Knight is a mere pest that must be crushed beneath your heel as you continue along your path to triumphing over the Prison of Elders and becoming legendary.
The first threat you’ll want to deal with is the powerful and deadly ogres. The best way to handle them in this fight is essentially to avoid them, so find yourself some cover. If you walk around the perimeter of the map, you will notice that a layer of rocks surrounds the center area. Hiding behind these rocks is a great way to stay out of sight of the ogres. You may also notice that the terrain on the perimeter slopes. Use this to your advantage. Some attacks can be avoided entirely by stepping backwards out of range. Just remember to keep an eye out for acolytes and thralls and headshot them quickly when they appear.
It will be difficult for the ogres to maneuver fast enough to flank you from the sides, but they won’t ignore you forever. Make sure that when they do begin to close in on you, their health is low enough so that you can destroy them quickly. The wizards are a little bit trickier to deal with. If you have three people in your fireteam, it would be wise to assign one player the responsibility of wizard duty. Abyss Defiant is the perfect weapon for this player, but if you don’t have it, just make sure you’re using something that inflicts solar damage.
One you’re comfortable dealing with the additional enemies, you’re ready to start directing your firepower towards slaying the Wretched Knight.