Catharsis is the final mission in the Bound in sorrow quest as part of the season of the haunted storyline. Players will have to complete the rest of the story to unlock this final mission. After Zavala, Crow and Caiatl faced their nightmares in the Sever quest and weakened Calus’ influence is when you unlock this final quest.
After unlocking the mission, Eris Morn will summon you to the crown of sorrow. And similar to the last 6 weeks, to continue the story you need to obtain Bound presence by running three tiers of Nightmare containment. After obtaining, Eris will lead you to the Catharsis mission which will pop up on the Castellum beside the nightmare containment on the Moon.
So here’s how you can complete this mission :
How to Complete Catharsis Mission in Destiny 2
You will start the mission in Castellum which is pretty straightforward as the objective marker will highlight where you need to go, kill the cabal guarding the door which leads you to Calus’ throne room. Follow the path and you will notice how much the leviathan has changed if you played the leviathan before it was vaulted.
Multiple nightmares will spawn in the middle of the Throne room, standing in the center will make the floor go down. Follow the waypoints and you will reach the underbelly of Calus’ ship. You will get confirmation from Zavala and crow that they have completed their amplifiers but will soon go into static as they are attacked.
You will spot only Caiatl waiting for you, once you place the harvester on the node, the final ritual begins.
Final Ritual
Once the boss fight starts, you will come face to face with all the nightmares you fought previously including Kethiks and Ghaul. In the beginning, you can use normal weapons to damage the fanatic but as the boss fight progresses, the fanatic will be invulnerable to normal weapons and can only be damaged using the sythe from the harvester.
Once you defeat the fanatic, return to Caiatl and get inside the shield as multiple skulls will home into your position. Defend Caiatl until the shield is dropped.
Kethiks and Ghaul will spawn again and you will have to defeat them using the sythe. Once you are done, a cutscene is played which marks the end of the mission and you will return to orbit.