i don`t know if that what found is a bug or not but my Seraph slave does extrem dmg up to 64k dmg (non crit and crit) and on a few types of enemys she does 0 dmg she is a valk with a spear
enemy typ that get 0 dmg are skeleton, rats, dogs, goblin that i kow of haven´t test every enemy typ
my other slaves make normal dmg and when i give my Seraph slave another weapon she does normal dmg