Insurrection Prime, Kell's Scourge

Insurrection Prime, Kell's Scourge is a Prime Servitor rebuilt into an immense war machine by the Kell's Scourge, and the final boss of the Scourge of the Past Raid.

Breaching the City
At some point, the Kell's Scourge stole technology from the Black Armory forge on Nessus and integrated it with their own technology, in order to create a massive War Mech for Insurrection Prime to commandeer.

Black Armory
After losing the Gofannon Forge on Nessus to the Guardians, the Kell's Scourge marched their forces towards the ruins of the Last City and occupied sections of it, using Insurrection Prime's mech to excavate the Black Armory Vault hidden within. In response, the Vanguard dispatched a fireteam to raid the Scourge's territory and destroy the war machine.

Phase 1
When the fireteam exits the Botza Underground and proceeds into the combat area, they will encounter a massive Insurrection Defender Servitor. They should leave it alive for now and split into two teams of three: a bottom team and a surface team.

The team at the surface has a simple task: kill the Brutal Shanks with elemental Absorption shields before they enter the bottom area, as well as the Insurrection Defender Servitor when the bottom team calls it out. Multi-element weapons are recommended for this role, preferrably Hard Light or Borealis to quickly deal with the elemental shields of the Shanks.

The bottom team has to run into the holes located in the four corners of the inner house structures and enter the tunnel underneath as soon as the Servitor is killed. Four different terminals that can be punched can be found down there, all sporting a different symbol and color: Triangle (blue), which gives the Angular Phase Radiance, Square (white) which gives the Parallel Phase Radiance, and Circle (pink), which gives the Continuous Phase Radiance. The fourth terminal pulsates in red and flickers between all three previously mentioned shapes; hitting this terminal triggers a wipe mechanic, so it should be left alone.

After each player in the underground area has acquired a different buff, they will call it out to the top team who will kill the Insurrection Defender and reset the terminals. The bottom team needs to once again find the same shape to punch; picking a different one will kill the player. Keep in mind that having a buff active creates a force field around the player which tethers and damages Guardians with other buffs stepping into it. The most effective way to avoid this is to rotate clockwise until everyone have found their respective terminal.

After everyone have gathered their second set of Phase Radiance, the top team should kill the Servitor to deactivate the electrical fields covering the exits. The bottom team split up and head to the three different energy stations identical to those in the first encounter. These are placed in the bottom left, bottom right and top middle of the area and spawn a Powered Drake Tank when two Phase Radiance charges are deposited. The bottom team needs take these to middle and shoot the Insurrection Prime, preferrably using the mini missiles to deal the most effective damage. The tanks have a 30 second timer and will explode once it runs out. The entire process repeats until the health bar is fully depleted and the second phase starts.

Phase 2
The second phase expands upon the mechanics of the first encounter. The fireteam should split into three teams: runner team, runner team 2 and map team. Before the encounter can be started, a Radiant Battery from a Berserker needs to be dunked in the console next to the entrance. The Insurrection Prime will then enter the arena and hammer the fireteam with several dangerous abilities. There are several shield plates that need to be destroyed on its body: two on the knees, one on the right shoulder, two on the back and one under the left arm. The team that is not running with Batteries should focus on taking down these as well as Fallen Vandals located on the rooftops.

A map similar to the one from the first encounter will appear in front of the entrance. The players once again have to locate the right Berserker and place the Batteries in the right places based on the callouts from the person monitoring the map. While this is going on, the Insurrection Prime will walk around in the middle, bombarding everyone within reach with rapid-fire Arc blasts. It also has multiple stronger abilities that it will occasionally use throughout the battle:

The first one is a volley of missiles launched into the air identical to those used by Elykris, the Machinist that track the location of the nearest player.

The second one is a cannon that shoots powerful Void blasts in rapid succession, much like the ones fired by Chimeras.

The third one is a charged explosive shot similarly to the one on Spider Tanks. This attack deals massive damage to players and can potentially one-shot a Guardian at lower Power Levels.

When any of these attacks are being used, an orange-red tank will appear somewhere on its back. Breaking this will stagger the Insurrection Prime, cancelling the attack and giving the fireteam more time to reach the damage phase.

After four Radiant Batteries have been successfully placed, a Drake Tank will spawn at all the tank plates around the area. One player needs to grab a tank and shoot the Insurrection Prime once to start the damage phase. The mech will kneel and the Servitor will reveal itself and its critical spot. Standing at the very back with Whisper of the Worm or D.A.R.C.I. is recommended for maximum DPS.

After a couple of seconds, the Servitor will send out an EMP blast that gives all Guardians a random debuff: Continuous, Parallel or Angular Phase Radiance. Standing together with a player with a different debuff creates a tether between them and causes damage over time, while standing together with someone with the same debuff triples the damage output. The most efficient way to utilize this is to create a triangle with three spots: C, P and A, with C to the left, P to the right and A in the back and having people switch as their debuffs changes throughout the damage phase.

After around 30 seconds, the front of the mech will close and the entire encounter starts over again until the Insurrection Prime is dead, thus marking the end of the Raid. If four damage phases have passed and the Prime is still alive, it will Enrage and wipe the fireteam.

Traits
Insurrection Prime is an aggressive, terrifying Prime Servitor, reigning through its massive war machine. With the mech by its side, it is the most powerful Servitor ever encountered by Guardian forces, requiring a team of six to bring its mech down. It seeks to bring down traditional Fallen ideals, and establish a new age of anarchy amongst their species by bringing down terror and hellfire through its mech. It is one of the most powerful Fallen combatants ever encountered by Guardians, only rivaling the likes of Aksis, Archon Prime in its combat capabilities.

Trivia

 * The mech bears a resemblance to Metal Gear Rex of the Metal Gear Solid series, and further possible inspiration taken into its design may include:
 * The Tone Titan from Titanfall 2.
 * Various classes of Titan from the Warhammer 40k universe.
 * It is the first mech seen in the Destiny franchise and the first Servitor observed commandeering a vehicle of any kind.
 * In Beyond Light live-streams, it seems that a enemy-class version of the boss will made a appearance in Beyond Light.
 * It is the first Servitor to be a Raid boss in the Destiny series.
 * Parts from various different Fallen technologies can be seen throughout the mech, with its head plate being taken from a Spider Tank as well as one of its weapons.
 * The word "Insurrection" means a violent uprising against authority, essentially rising against the traditional ways of the Fallen. It is one of the few Fallen to not bear a traditional name ending with -sis, -is, or -iks, demonstrating its abandonment of tradition.
 * Aside from the raid lairs, Insurrection Prime is the sole boss (that needs to be damaged) of the entire main raid.
 * The actual Prime Servitor that controls the mech bears a similarity to the Mad Warden Servitor.
 * The Insurrection Prime is one of few raid bosses that has multiple encounters. Among them being Aksis, Archon Prime, Vosik, the Archpriest, Argos, Planetary Core, and Consecrated Mind, Sol Inherent.

List of appearances

 * Destiny 2
 * Black Armory