Season of Dawn in Destiny 2 involves helping Osiris as the Red Legion attempts to reclaim their sundial from Mercury. They want to change the course of history and try to do so, so they won the Red War. At the end of the Sundial mission, you have to face a boss. The first boss is Niruul, the Hollow Voice.
When the Guardians enter the chamber to confront Niruul, the terrain is wherever it is on a lower platform. Niruul moves back and forth at this location, shooting players and periodically becoming immune to damage. Throughout the encounter, The minions appear throughout the Grunt of the Red Legion, The Beasts of War, The Gladiators, and The Psions.
Niruul will trap players in a purple shield to prevent them from moving. Once locked behind this shield, you have to shoot the little circles on the shield to escape it, and you have to shoot them quickly. If you don't, the shield can shoot you on a hit. If you are healthy, you only have part of it. You can help your teammates escape theirs by shooting the circles outside the shield.
Occasionally, Psion's commanders appear in the arena. They should come down in a single melee hit, so you need to get in close. If you have trouble locating them, look for the translucent bubbles indicating where they are floating in the air.
When Niruul reaches a fourth or a third of his total health, the enemies of the Honored Colossus enter the battle. You can usually find them hanging on the left and right sides, so get them out quickly. Try to obscure their field of vision to make it a short job. Don't waste your ultimate on them, however.
Six Guardians fight against Niruul and his Red Legion minions. Not all party members should be focusing on Niruul as the minions continue to enter the fight, and if you don't clean them up, they can potentially overwhelm you and your team.
After taking out Niruul, you return to the Sundial to claim your reward.
