1) If I make a Death Hag my BSB, they can still be mounted on a CoB right?
2) What units can the cauldron of blood join? The rules say it joins units in the same manner as a character, but the character rules say characters riding chariots can't join units. I'm assuming that rule is overridden, but how? Can it join the units normally allowed to characters (e.g. can I put it in with my cold one knights?). As a chariot, can I also join it to other chariots?