Some of the hardest bosses in the Dawn of the Infinites Megadungeon have been massively nerfed on the Patch 10.1.5 PTR.
Note: There may be more health nerfs throughout the instance but we are unable to verify this at the moment.
Patch 10.1.5 Megadungeon Boss Preview
Chronikar
This boss has received some massive nerfs, completely removing the majority of threat on this encounter.