Has Batman ever fought the Devil, and no not Daredevil, but Satan himself?
Doctor Hurt was a member of a satanic cult, and he thought that the demon that appeared before him was Barbatos. In all actuality, it was the Hyper-Adapter, released from Darkseid's Ancestor Box. The HA wasn't actually the devil, but it did make Hurt immortal and, I think, more crazy.
I don't believe Hurt was really the devil, just that he's often referred to that because he's so sinister.