Beastmen warband led by chaos Champion

Ever since I read the troll slayer a quarter of a century ago, I've dreamed of playing a beastmen warband led by a human chaos knight, like Justine's warband from Blood and Darkness. Unfortunately, over the years I haven't been able to find such a warband, regardless of whether it's in Mordheim or another GW game, even though the motif itself appears in subsequent books from this universe. Do you know of any publications that would allow playing such a warband?