Skeleton mage dealing insane amounts of damage

Hey dudes,

I've been noticing this for awhile but now that the random instadeath mobs have been removed (good riddance archnemesis, and they fixed some other stuff that predates it too) it's a lot more obvious.

The skeleton mages that shoot like 3 projectiles at once, the slow moving fireballs, those skeletons seem to do WAY too much damage. Like, one of them just gibbed me from damn near 100%. It's a dark-colored skeleton and it was named "Bone Warden". It has basically no hp and dies in one hit. This thing blasted me to smithereens through aegis aurora like I was a sheet of paper

I'm in a T11 map with just minor blue enchants on the map, inhabited by skeletons, monsters gain power charge on hit, players have less accuracy, players have less AoE. There's no reason this little trash mob should be dealing thousands of damage.

I have over 13,000 armor, over 3,800hp, and over 2,100 energy shield. My resists are 80 fire, 86 cold, 81 lightning, 75 chaos.

I have 72% chance to block attack damage and 42% chance to block spell damage


does anyone know if this is NOT a bug and if there's anything I can do to mitigate this damage? Is it fire damage or is it true damage or chaos damage or something? Am I stupid?