Bear in mind, I don’t read the books just sometimes dig myself into the Warhammer Wiki:
Considering the bosses our heroes already have slain:
Bödvarr Ribspreader - The Champion of the Rotblood Tribe.
I guess he is more powerfull than your average Norsca Chieftain? I don’t believe him to be a serious Champion chosen by Nurgle…
He seems to me to be strongest of all Lords (Except maybe Rasknitt WITH his special play-thing)
Bubblegum Homeopathy - a Chaos Sorcerer (I think not strictly belonging to the Rotblood Tribe)
Seems just like your average wanna-be famous Chaos Sorcerer worshipping Nurgle.
Skarrik Spinemanglr:
You average Skaven Warlord of a minor Skaven Clan.
Rasknitt:
An average Grey Seer of a Skaven Clan.
So I do believe why not?
I mean I can’t find anything about “Master Assassin” my mistake, what about your “average” Eshin Assassin?
Already started such a discussion here…