You know when the newscaster says other gangs are coming into town to compete against Batman?

You could use bits of the hated Batman And Robin in there to make out that the Riddler and Two-Face aren't the only problems hitting Gotham at the same time (taking snippets of footage from it is probably all you can do with that film).

Maybe Two-Face has to compete with another gang for a chance at killing Bats.

UV Skullface could be replaced with a more prominent featured villain and at the end of the film the dynamic duo could go off to finish that fight.