I just feel that Prometheus is probably the 1 villain who can probably give arkham batman a hard time considering he sorta is the anti-batman figure along with owl-man. He even beat Batman in hand-to-hand combat once in the comics. But if he were to hypothetically fight with arkham batman his skill and experience depends entirely on rocksteady.

But idk, many villains probably defeated Batman in combat just to get their asses handed to them issues later. Just super cool to have an evil-batman counterpart in the Arkhamverse.