General Sargas Ruk's battle is divided into three phases, each phase begins at every 1/3 increment of his health. Defensively, he has heavy armoring impervious to damage except for one weakspot, which will appear on various locations depending on the phase he's in. But as wearing a pyro-amputation naturally goes, his exhaust will occasionally open to flush out heat in blue flame, which is his only vulnerable point. His exhaust is however, still high in armor.