The Emperor Calus final boss fight in Destiny is a more straightforward encounter with just one simple twist. The fight kicks off with a room full of enemies that will spawn from the door under Calus and from the back left and the back right. You want to concentrate on getting ammo as much as you can. Power ammo can be collected from any of the orange bar Major enemies as well as from melee kills on councilors when they appear on the plates prior to teleportation.
Once the party gets teleported you want to split into two groups of three. Assign 3 people to grab the orbs and return to Calus and 3 people to stay in the Void Dimension. The three in the Void dimension have to multitask. In addition to killing the Psions that appear, they have to call out the three symbols that appear on the forehead. Each person left behind will have a different symbol. Pick an order in which each of the three players communicates to the raid which symbol they see. It’s important to do it in order, one after the other and not at the same time. These 3 people must not jump and be careful not to slide into any of the ramps when they get pulled forward. In addition to shouting out your symbol, you must kill Psions. Initially there will only be two floating white ones. You must kill them fast. It’s important that you don’t jump into the air and stay behind the barricade.
Back in the Calus room, the three players who grabbed the orbs and teleported out must continue to kill mobs. They will see the 4 councilors on the pedestals around the room. While killing the enemies listen for the symbols the people inside the Void Dimension call out. There will be one symbol not called and one of the players must enter the bubble and take that councilor out. Doing so will move the barrier forward in the Void Dimension. Continue taking out the enemies while waiting to hear the symbol callouts from the Void people
Meanwhile, back in the Void Dimension, the barrier will move forward and move symbols will appear. Continue calling them out and in addition to the 2 white psions, you will have 3 red health bar ones on the ground. Prioritize taking them out first and then the floating white ones. The person standing in the middle will need to assist the people on the left and right as they may not have line of sight on the small psions. Let gravity pull you closer to the barrier as it moves ahead but don’t slide up a ramp and during any phase past the first, watch out for holes. After calling the symbols and shooting the psions, position yourself for the decent forward. After the 3rd set of symbols you will reach the end with a few more psions. At this point you will start seeing skulls pouring out of the mouth. For each skull you destroy, you will earn one stack of Force of Will. This part will make or break it for many. You want to get at least x50 or in our case, x80 on one phase. We found that using the Coldheart Trace Rifle to be the best for the job. Before shooting the skulls, move backwards and get closer to each other.
Meanwhile, back in the Calus room, the three people there will need to shoot the armor off of Calus. You will him starting to glow while the other group is shooting the skulls. You can allow that group to kill more skulls if you wait before shooting at Calus. This will mean that he will really start glowing before you start shooting him but you will then need to shoot him to have the other group return. Once the skull portion is done the 3 people in the Void Dimension will return and there will be a glow on each of the 4 plates around the room. Select a plate for the group to meet up at. For us, it was the back right corner. Gather everyone around and have everyone jump up together. You now are in the burn phase of the boss. This is why you’ve been collecting power ammo so use it. The Coldheart also does good damage. You will do far more damage with you have a higher stack of Force of Will. You can’t stay on the plate for long. You will eventually see Calus raise his arm up and you will need to jump off together and go to the next platform as Calus will bombard the plate. Continue in the same manner until he shoots at the 4th platform.
Once you have taken off 1/3 of his health, he will transition to a newer form. During this transition he will kneel to the group opening up his chest. This is his new critical damage spot. Up until then, it was the head. Remain on the plate during this part and wait before jumping to the next. Once you finish the 4th plate, you will repeat the process from the beginning by starting off clearing the room of enemies before getting teleported once again. It’s always a good idea for the Void group to use their suppers when the area is filled with enemies so they can create orbs for the 3 people who have to fend off the enemies while killing councilors.