Alchemist debuffs & Xy'zzy

[cru121]

So I was in a LN group for Legendary Hound of Xoriat.
Alchemist has a bunch of debuffs that reduce PRR, MRR, damage, speed, spell power, etc.
It looks like Xy'zzy was immune to everything.
Is this working as intended?

[Zeratide_]

Xy'zzy has always been immune to nigh everything

[Mglaxix]

Xy'zzy is so powerful that you cannot damage her at all except by turning her three demon hound spawns against her. As you enter, there are mindflayers that come out of the portals that drop shards that allow players to charm the spawned hounds and force them to attack their mother, whittling down the boss's health to a point where player attacks will work.

[Tom116]

Once Xy'zzy has been reduced to 25% hp, her immunities should drop. Before that she's basically untouchable, just part of the normal mechanics of the raid