Question about Blood Magus enemies

Necromancer
1

I haven’t done a lot of research into the best builds ive been trying to just make stuff up as i go. My build is set up to use lucky hit to stay in blood mist pretty much all the time while it detonates corpses with an aspect. I also use bone storm to stay barriered and corpse tendrils to apply vulnerable. Im level 79 and I’ve been doing pretty good so far in nightmare dungeons as far as i know.

Once i got into upper 40s lower 50s tier dungeons I have, on three occasions, run into a champion Blood Magus that is completely indestructible. I’m not sure what combination of modifiers the dungeon or the magus had i should have written it down. When it happened i just ran or kited it around for the rest of the dungeon until i finished it then portaled out.

My question is what is causing this? Is it a bug or am I doing something wrong?

2

What was your issue?
You did no damage?
It healed all the damage it was taking?

3

Its health bar did not appear to move at all. Everything else in the dungeon melted pretty fast once i got tendrils down elites included just not these blood magus guys. It was just one champion blood magus in three separate dungeons.

4

Did it perhaps had the suppressor buff? (blue barrier around it)? The tendrils should have worked even then, but if you’re attacking it from outside the barrier, it won’t do damage.
Else, I don’t know what could be.

5

Could be vampiric, life steal, or the 1.5% hp regen. On champions that can teleport, it’s horrendous to deal with if you can’t stunlock them on a big pool of shadow.