With the Season 8 PTR now live, new assets have been discovered for Bosses, including the model for the stunning new Belial encounter!
Season 8 PTR Patch Notes
Harbinger of Hatred
Urivar
Belial, Lord of Lies
Belial has two forms, one for when he assists other Lair Bosses, and his ultimate form for his main encounter
Belial’s Lesser Form
Belial’s True Form
Other Minions
At this time it’s not clear what encounters these models are a part of.