Like in GD for example. Cause honestly, this Lagoon boss Ive just beaten, man I dont think I had such problems with a single Grim Dawn boss or a nemesis on Ultimate. No joke. The 3d phase is just nuts, It is really hard to avoid one-shots
EDIT: probably the closest comparison that comes to mind in terms of difficulty is Shaper from poe. That giant yellow ball of death and the purple stun still haunt my dreams