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Val Ca'uor was a former Val who became the de facto leader of the Red Legion following the death of Dominus Ghaul during the Red War. Eight months after Ghaul's death, he ordered a massive Red Legion fleet to attack the Leviathan, causing Emperor Calus to request his assassination by a Guardian raid team. He was subsequently taken down in an unsanctioned raid op by Guardians aboard the Leviathan's spire, marking the apparent end of the Red War. He is the final boss of the Spire of Stars Raid Lair.
In the vacancy that was left behind by Ghaul's death, Val Ca'uor took advantage of the power vacuum and quickly asserted himself as the commander of the Red Legion. In an effort to rearm the Red Legion, Ca'uor ordered his forces to Mercury and Mars, which had Vex technology and ample energy respectively, in addition to a soft Guardian presence. After Xol, Will of the Thousands was "defeated", Val Ca'uor led a fleet against the Leviathan in order to kill Emperor Calus and seize the ship for the Red Legion's purposes. His forces occupied the Spire of Stars, and they raided the spire and killed many of Calus's troops and commanders. Ca'uor was intercepted at the Celestial Observatory just as he struck down one of Calus's robotic proxies. In the following battle, he was overpowered by the team as they use the Leviathan's defenses to destroy his fleet, killing him in a final showdown afterward.
Val Ca'uor's encounter is very structured like a game of hot potato, building upon the previous mechanics of the Spire of Stars Raid Lair. Ca'uor will initially be immune to damage and will attack with his Magma Launcher as well as summoning waves of ads. After some time clearing the adds, Ca'uor will glow purple and will launch a ball at one of the four plates. At this point, everyone in the fireteam will get the Engulfed debuff, which must be removed before the 15-second timer runs out. To do that, all players must pass the ball around between each other, and the last player who obtains the ball throws it at Ca'uor.
Once the first phase is over, three random players will obtain the Superior Retainer buff. The plates in the front of the room will have red beams of light on them, signaling that a Gladiator is coming down via drop pods onto the plates. Once the Gladiators are down, four players must stand on the plates, and one of the Superior Retainer buffed players must go up the red light shaft in front of Ca'uor and call out which ships need to be destroyed and their corresponding symbols, as with the previous encounter. At this point, two more balls will be launched at two random plates. Two other players must take the balls to the mist in front of Ca'uor, and will be afflicted by the Greed debuff. They must throw it at the fireteam members standing on the correct symbols, who will then throw it at the generators to arm the Leviathan's weapons. After this is done, the plates will receive two more balls players and must throw it to two Superior Retainers, who will then run into the mist, and throw the balls at the ships that were previously called out.
Once both ships are destroyed, a new ball will spawn. The fireteam should ideally make their way next to the large, orange window behind Ca'uor, with one player as a designated "quarterback". The quarterback will get the ball, engulf it in the mist, and throw it to a player. The remaining five players will play hot potato, passing the ball as their Greed stacks increase. After the second ball spawns, the teams should divide into two teams of three, and then divide once more into three teams of two when the third ball spawns. The quarterback will take the balls through the mist and pass it to the other players. Finally, the Calus robot behind Ca'uor will rise up, start floating and raise its hand. Whoever has the balls should throw them at the Calus robot's hand once it turns purple. If successful, Ca'uor's shield will break and he will stagger.
The fireteam should split into two groups and head to the back rooms. Ca'uor will turn and fire missiles at players, but the back rooms will provide a lot of cover. His weak point is the tank on his back, so at least one player must distract Ca'uor. One way to distract him is have a top tree Arcstrider with Raiden Flux jump up and slam him repeatedly, stunning him and preventing him from launching missiles, as well as leaving his tank open to fire. Another way is to have a Sunbreaker Hammer Strike then activate their Super and hit Ca'uor with it. Warlocks should be in the rooms with Empowering Rift, and everyone firing at him should be using weapons such as D.A.R.C.I. or Whisper of the Worm. Gathering the entire team into a Well of Radiance to fire at Ca'uor is also an effective strategy, as the tank is still somewhat visible from the front. If he is not taken down in this phase, the fireteam will start a new damage phase.
Once Ca'uor's health is depleted, eight orbs will be launched across the room. All players must grab an orb each and throw them at Ca'uor to defeat him and complete the encounter.
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