Notice anything missing from Mechanno Lord's debuffs? Should be to the lower left of my ICEHud. No Diseases. Damn thing was immune.
No diseases means no self healing. It also means I don't hit as hard. To compensate I put more focus into maintaining my mitigation cooldowns cycled. I also changed my rotation to be BS and OB only for runes. BS to convert the bloods to death and Obliterate since it plain hits harder and I was no longer worried about cleansing my own diseases.
Had it gotten real hairy I could have called the army out. I also still had lichborne in reserve. As it was, I downed him with about 6k health left but by the time I was around 10k health I knew I was winning the DPS race.
The rest of mech was easy. The mini gauntlet to Panthelon was fun, but they were spaced well enough I could keep my self healed and only fight one group at a time.