Yellow Sphere?

I guess it came with around patch 1.1.4.0:

Undead sometimes have a yellow sphere above them - What is that?

A buff from something I guess.

I’m sure it’s a buff given by the skeleton priests.

I was also shocked that blast shield now gives us a yellow/ orange sphere, praise the Artist!

Of course I also assume it´s a buff.
But does anyone know what it does?

grimtools is our friend

https://www.grimtools.com/monsterdb/1217/skills

now im not so sure myself if this is the actual one

Ah, wasn´t thinking of that.
So all dmg / health / ele resist maybe.