I'm 100% sure that (uber) arbiter of ash becomes easier if you die.

Uber arbiter of Ash has way less hp if you die to him, i do 3m damage in the first few seconds and it only takes like 20% or his total hp, but if i die, that becomes like 70 to 80% of total, and it still says only ~3m total damage, i will try to screenshot it.
Loot also seem to not change as i still get occasional diamond drops even if i die to an instant one shot mechanic.





first pic it shows 3.7m damage but only 20% of his hp, second shows even less (3m damage) but it took almost all of his hp.

Both screenshots were taken after the initial fire beam completes and he does his second move or moves into second phase if enough damage was dealt, so about the same time of dpsing.

I'm submitting this because i want the hard challenge just in case the loot may be affected lol.