Blackwing Lair disappearing bosses

[xXMendonza]

Some bosses on BWL fade and disappear when i attack them. Some like "Vaelastrasz the Corrupt" appear again after a while and are killable but Nefarian fades and disappears on the final encounter right after his speech, it wont even let me attack him once.

[vinto]

Killable? i can't down the first boss,on 0.1% hp it just vanishes n resets ...**** keeps going on tried 20 times.

[Commandantx]

Did u clear the 1st room? All the eggs?

[Cyclowned]

Destroy all eggs in first room, then kill the boss and u have to kill all other bosses too.

[Mr.Fordragon]

Yep Blackwing dissapears,i did that raid last week and done all it "requires",and we got him down to 80% of hp,then he came under that ceiling and every attack we had was evaded,boss froze and after 1 min he dissapeared..and raid was over

[Apsiputes]

https://www.youtube.com/watch?v=eqEeqPfL9mA&t=70s It's guide how to solo 1 boss