I don’t see it awkward for you to play bat and Robin. They are the dynamic duo.Well, Lord Wayne IS the Black Bat of Gotham. He's the one out in Gotham with Robin hood. That's why it would be awkward for either of us to play him.
Injuring is fine. Maiming is fine. Killing is still not fine.
Would be a bit worse if I was to play Batman and joker as I’d be deciding who wins each time aha