Prince Hylas is the fourth boss encounter in Greenscale’s Lair.   Within the first 15% percent of fighting Prince, he will spawn the three bosses faced earlier, each of which has a reduced subset of the abilities they had when faced earlier in the dungeon.  First, a weaker version of Duke will spawn and an off-tank needs to pick him up immediately.  All DPS can get off one round of rotations on Prince before they must switch to Duke since Prince picked up one of Duke’s abilities: Prince’s Wrath.  Prince’s Wrath will one-shot any member standing within its radius.  After Duke spawns all DPS should switch to him and kill him.  Duke does not do any new abilities other than an AoE on the ground that DPS can stand out of and still DPS the boss.  Soon after spawning Duke, Infiltrator will spawn.  Once Infiltrator spawns, Prince gains a new ability: AoE polymorph.  This polymorph will target an individual raid member and polymorph them.  A ring appears around the raid member and any additional raid members within it’s radius will also be polymorphed after 1.5 seconds.  All DPS need to switch to Infiltrator after Duke is killed.  A third tank needs to pick up Infiltrator. This second off-tank does not need nearly the level of equipment of the other two tanks due to Infiltrator’s random teleportations.   Duke needs to die quickly as Oracle will spawn soon after he is dead.  Once Oracle spawns, Prince gains a new ability: a massive raid-wide AoE damage-over-time (dot).  All healers need to use any abilities they have to shield themselves from this AoE so they are able to quickly heal up the raid.  If any raid members are not completely full health when the AoE goes off, they will most likely die from the second or third tick of the dot.   Below is the tanking locations for all three adds and Prince himself:

The large empty space below where the bosses are tanked is where all healers and ranged DPS should spread out so they can avoid the polymorph. Infiltrator will cast landmines that DPS should do their best to avoid because if they get hit by one and then Prince casts Soul Fracture, they will likely be killed.  After Oracle is killed Prince enters phase 2. During phase 2 all raid members are turned into critters and must run back into Prince’s room.  The entire time Prince is casting a long-channeled heal.  This heal must be interrupted by DPS.  15 seconds after the channeled heal is interrupted, Prince will spawn two tree adds that must be picked up.  At this point the fight turns into a DPS race as other adds will continue to spawn throughout this phase.  Prince must be killed before the adds overwhelm the raid.