They use to be CC'able, however it made them extremely easy.
The last beta they became CC immune and got health buffs all the way around, as well as the "rage" mechanic actually working better than it did before.
Personally, for its intended level, its overtuned compared to say.. Cadamimu. (Or however you spell that place)
Just remember not to save the Consular for last, as Earthquake will wreck your **** up. Same with the Trooper. We usually go Sent -> Consular -> DPS both BH/Trooper down to about 10%, then burn Trooper and BH last.
Thank you. Finally some sense in this thread.
On the first run (the one with the 22 in it) we only killed it because it bugged and only left the Trooper and Smuggler up.
On the 2nd run, where everyone was 25 (think the other Juggernaut dinged midrun though so 26 perhaps) we went Sent -> Trooper -> Consular -> Smuggler. Was pretty close even with the aggro-dropping Sentinel out of the picture early.
I'm not crying for nerfs, but if this is the intended difficulty you may want to bump the other 2 bosses to this level for consistency purposes, because the first and last bosses feel like utter pushovers compared to this fight. The last boss is arguably easier than anything in BT/Esseles, even.