Hi Guys,
I’ve encountered a Legend Enslaver and he does not die. I am able to make his health bar to zero but after 10mins of fighting, he still does not die. I just quit the map out of frustration. Is it a bug?
there is a Map Affix for Challenge Maps that lets enemies on a Map heal 1% to 5% of their Max HP every second.
what you should do is check Maps to see if it has the Heal affix. if it does, use Larimar to change the Maps affixes to affixes you are happy with.
for lower floors, increasing your characters DPS is the other way to go. on higher floors, it gets to the point where enemy Heal will never be beat.
I have been plating for many years, so floors 200 and lower my DPS is good enough to kill even Mythic monsters with +5% Heal, but for floors over 200, I use Larimar to change Heal to something else. better safe than spending 20+ minutes fighting before realizing I need to quit the Map.
damn. i did not see the affix. i just focus on pack size. it takes much time to summon one legend enslaver 
Codex > Dictionary > Enemy Affixes and Map >
these will show you what you are up against when fighting monsters and fighting monsters on Challenge Maps.
with Accomplished Perk, I need to slay 38 Epic Enslavers to get the Legend, slay 8 Legend Enslavers to get the Mythic, and slay 1 Mythic Enslaver for an Eternal Pet.
Mr_Scooty did some tests, and later in the Thread, he has an update for Patch 3.0 and some more tests. one of his tests was for spawning more Enslavers. take a look.