nightmare i was able to beat the trial by fire multiple times solo and face tank most of annihilation. I could still die and died to sha la a bunch of times. Also beat kauela on nightmare with this build before it even summoned any tentacles. Apocalypse i have only managed to beat triple threat and not consistently. i am still trying to find a tank build that can tank everything in apocalypse while offering good clear times. For an unkillable build you can use redeemer and gift of the forest combo for infinite relics and constantly heal massive hp for 20 seconds with resonating heart with only defensive rings but it lacks dmg I have a full defense prism and im currently grinding the legendary to get 50 hp and stamina. I believe it should give me the survivability to let this build tank in apoc cause it does soo much dmg already.