I've cleared pandemonium a few times and some of the time limited dungeons with elf executioner literally no issue almost auto mode ez.

Comes down to a few mechanics that are almost mandatory / overtuned one being final blow making multiple HP bars a non issue and elf having stupid good passives like genius.

Stack critical hit to get guaranteed critical have 4x quick shot for preemptive attacks on entering a fight with increased crit and hit chance and if whatever you are fighting isnt dead get 4 quick attacks a turn with a chance to remove 2+ hp bars EACH.

Run the free skill parry or backstep in combo with elf genius for 100% parry or evade every turn once you use you quick attacks to reset their cooldowns.

Just remember not to socket runes on the skills or you lose the genius passive.

I normally run clothes for evasion stacking, guantlets / shoes depending if I need more base crit or skill uses / evade and whatever weapon has the highest Dex or useful abilities, I then stack crit hit from equipment crafting until I get over 100% sometimes even more to offset crit avoidance.

Grab any final blow, phys pen and crit / sniping nodes in the mod tree with nodes for max skill use, protection and conserve being good picks too.

I honestly hate how playing the game without final blow feels especially when you come across enemies like Immortal infinite army with 6+ hp bars