I wrote this up a while ago after my first few prestige runs, but I don’t think I posted it. With the light level change to 300, I figure this is as good a time as ever.

The prestige variant of Calus encounter at the end of the Leviathan raid only has one mechanical difference from the normal difficulty – whoever punches a psion in the throne room (to create the next barrier in the shadow realm) is teleported into the shadow realm immediately. A random guardian currently in the shadow realm is simultaneously teleported into the throne room.

Split:
As with a normal run, the fireteam should be split into two groups: the throne room team (2 guardians, preferably one is a stormcaller with healing rift) and the shadow realm team. (4 guardians, preferably one is a titan with rally barricade). We use 4 guardians in shadow realm because at any given time one of them will be in the throne room due to the teleport mechanic. If we have four guardians rotating through the teleports, there will always be 3 guardians in the shadow realm to see and call out the raid symbols. That leaves two guardians always be in the throne room, allowing you to ensure one or both of them has a healing rift and roaming super.

Throne Room:
The throne room team has a simple job, but it can be hard to execute on prestige: stay alive, kill all enemies as quickly as possible, and drop Calus’s shield when all the enemies are dead. While in normal difficulty the throne room team can work independently (one left/center, one right, and one on cleanup/psion punching duty), the increased difficulty of the enemies to fight makes grouping up for team shots more effective. The guardian pair should remain on the right side of the room, using the sun platform and pillar for cover initially as they kill the enemies. Let the left side enemies come to you (though a rocket or grenade can work well for the center door). Fall back to the dog platform as necessary, and fall back again to the brazier platform as necessary. When the shadow realm team calls out that the last projections are dead, pop roaming supers to clean up the remaining enemies and get in position to drop Calus’s shield. Use a healing rift if possible to extend the duration of the shield phase.

Shadow Realm:
At any given time, there will be one person from the shadow realm team in the throne room (the "puncher"), and three people in the shadow realm.

Puncher:
The shadow realm team member in the throne room is responsible for punching the correct psion. This creates the barrier their teammates need to survive, teleports the puncher into back of the shadow realm, and teleports one of the people in the shadow realm back into the throne room. While the first psion can be punched immediately, the “puncher” should not punch the next psion until they hear a “clear” call from the shadow realm team. This prevents the puncher from prematurely teleporting a guardian that may be in the midst of killing a projection or psion. That being said, if the people in the shadow realm are slow to call out “clear”, the puncher may need to melee their psion anyway to create the next barrier. To manage this, the puncher should be waiting for the “clear” callout while standing inside the bubble of the psion they need to punch. They should watch the inner bubble grow in one of the other psion bubbles in the room. Regardless of the callout they must get their melee in before the inner bubbles meet the outer bubbles (since that’s when the current barrier disappears).

As soon as the puncher melees the correct psion, they’ll be teleported into the back of the shadow realm. They must jump and dodge any ramps or holes as they’re sucked to the front of the room. On the way, they should glance at the symbol on Calus’s forehead and call it out. They should also be firing at the center psion in the shadow realm.

In the Shadow Realm:
There are new callouts and behavior for the people in the shadow realm team related to the teleportation mechanic. As with normal mode, it’s still critical to kill the initial psions as soon as possible (to prevent a grenade), and still critical to kill the projections before they wipe the team. Unfortunately due to the teleportation mechanic, there’s usually only two people ready and available in the shadow realm to take care of both tasks from the current barrier. For that reason, you want to be sure that the two people remaining in the shadow realm are taking care of the left and right psions (as they tend to throw grenades first). You also don’t want anyone teleported prematurely, as that might leave a psion or projection unattended.

To manage all of the above, there are two new callouts: The first callout is easy - when both projections are dead, the shadow realm team should call out “clear” to indicate to the puncher that it’s ok to teleport and create the next barrier.

The second new callout and behavior is a bit trickier, so first some background. In a normal run, the left lane person should be firing at the psion in the right lane, and the right lane person should be firing at the left lane psion (while the center person shoots the center). This “cross-shooting” at every barrier ensures that the psions are taking damage as they spawn in and prevents a grenade from pushing a guardian over the barrier. The left and right psions are much more likely to be the first ones to throw grenades, so they must be prioritized.

With the teleport mechanic added to prestige mode, there will only be two guardians at the barrier ready to shoot psions and projections. They must know as soon as possible which of them should shoot the right psion, and which of them should shoot the left psion. That means that when a random person in the shadow realm is teleported back to the throne room, that person must immediately call out which lane of the shadow realm they were in ("left out", "center out", or "right out"). If they were the center person, nothing needs to change – the puncher returning to the shadow realm starts in the center and will assume the center role. However, if they were on the left or right side, the person currently in the center role must shift to replace the lost side. If the left lane person was pulled, the center person is now the left lane person and they must shoot the right lane psion. If the right lane person was pulled, the center person is now the right lane person and they must shoot the left lane psion.

When the psions are dead, the shadow realm team should team-shoot the projections in the order they appear (it alternates left first, right first, left first, right first, left first). At that point the returning shadow realm person should be ready at the center (with their psion dead) ready for the next barrier.

Note that most teams are used to a left-to-right symbol callout order (left, center, right). For prestige mode where the center person just teleported in and is busy dodging ramps and holes and shooting their psion from a distance, it’s faster to call out left, right, center.

As soon as someone is teleported into the throne room, they should throw a rocket at the center door below Calus to help clear any adds there. Don’t worry, you get the ammo back when you punch the psion. Then get inside the bubble of the psion you need to punch.

DPS:
The DPS phase is not substantially different from normal, but there are optimizations that should be made if possible:

• Start damage from the dog plate – this is closest to where the shadow realm team returns and thus DPS can start faster. Since there’s a fixed time to do damage before Calus becomes immune, these extra seconds might matter.
  
• Use a countdown to ensure everyone gets on the first plate at the same time.
  
• Use a rally barrier and empowering rift to fire all rockets from a single plate. On the first or second plate, a Titan can put up a rally barrier. Skipping reloads using the barrier allows everyone to fire all 5-6 rockets at Calus from a single plate. Combined with an empowering rift, this can be enough to drop Calus’s health by half. If this is done from the first plate, the Warlock’s empower rift should be available for the 4th plate.
  
• Grenades and golden guns should be thrown from an empowering rift if possible.
  
• If you just have a single warlock, they can switch from healing to empowering as soon as Calus’s shield is down in the throne room (and back to healing during the ad clear phase).