BB/Tamamo (caster)/Waver would be a good arts setup since you can't lean on double Merlin. I can't remember if you had Tamamo or not. You should be able to NP with BB often with that setup.I never got BB because I wasn't far along in the story when it happened. I need to finish Babylon now, but it's slow going. Not too interested in the story and I've skipped a good chunk of it...except the Ishtar stuff since I think she's a funny character as opposed to the other characters. I wish I had someone to deal with Avengers, but alas. They take forever to kill. I remember seeing a few friends with BB on their list, so I might give her a shot to see if I can beat the dog guy.
I beat that Medb quest last night, it was way easier than I expected, I was psyching myself up too much about it. I accidentally grabbed a Waver instead of Merlin so I ended up beating it with Waver/Waver/Merlin/Raikou (berserker)/Mash and Cu (lancer). I ended up swapping out one of the Wavers with Cu towards the end so he could finish off Medb just for the memes. I think it took me 8 turns. I like her new costume, but the first ascension is still my favorite with the fluffy boots.