Событие "Древнее Узилище". Ancient Prison event

Beleth, Immortal of the Storm is a Unique Oppressor found in the Pandemonium Fortress Level 2 in Act V of Diablo III. He spawns for the Ancient Prison event, as its final boss, and killing him is required to end it. In combat, he has Orbiter and Frozen Pulse affixes. It is the only unique monster in-game that was changed to its pre-release state in a content patch.