This guy is annoying for casters:


So to say what i know.

First 3 attacks of a battle: Nothing (may even be first 3 attacks onto this mob)
Sometime after this, the mob will stop taking magical damage.
Sometime after this, the mob will absorb incoming magical damage and add health to it instead!
After hitting it with melee around 5 times it seems to lose its absorb/shield.

Is there a more precise method of dealing with it after it uses its shield?

Would be nice if they updated monsters with this ones data if someone has figured it out as i did look there first
https://ladderslasher.d2jsp.org/index.php?g=21

A good way to beat this mob would be to equip any other element or melee it down. This monster is the ice immune--every element type has 1 monster that can heal from it sometimes (annoyingly often), except for fire that is... there are 3 immune monsters for fire lol

cheers. that helps although is there any specific pattern to its immunity/absorb?
Would rather not ferry around an item to deal with it if i dont need to. I sometimes just reset as he doesnt turn up that often.

Best way of dealing with him is killing him as he appears as the first 3 attacks seem to always go through. Although i could easily be mistaken here

Mobs need to use an ability to become immune
Once they are swap element or to melee