just a little lore insert here… i think karros adal is karroz the sigil of chthon. remember when you kill karroz he shouted “no, no, NOOO!” then explode and summoned a chthonian unraveller? coincidentally, near karros adal in bastion of chaos, there is a chthonian unraveller guarding him. i think the unraveller is angry with karroz’s failure, then it tortured him. turning him into skeleton and damning his name.
this kinda makes sense, since in mournwald there’s a chthonic rift that leads into a void place where you found three bloodsworn imprisoned. they plead you to rescue them, since there’s a blood keeper wanting to torture them for their failure. seems like there is no rest for the bloodsworn.