[quote=@Roman]
'Any other batvillain apart from arguably the biggest DC villain of all'

And I guess my dream of writing Harvey's fall is down the drainpipe too.

¯\_(ツ)_/¯
[/quote]

Characters are on a first come first serve basis including those being used as NPCs. That said NPCs must be in use during the arc otherwise it's character squatting which I won't allow. GreenGrenade's first arc is Joker heavy if I'm reading into his first post correctly and along with a mention of Riddler I assume he also means to use Two-Face.

That said! Due to the allowance of different time periods I see no reason why you two couldn't come to an agreement on at least one of your interested characters, particularly in Two-Face's case as you want to write his transformation which I'm presuming is not part of GG's Bat arc. 

If I'm wrong there's unfortunately nothing I can do here without abusing my authority as a GM which is something I am unwilling to do as it would spoil the RP for far too many players. I'll do my best to accommodate those who are interested in characters in use but ultimately this is a first come first serve basis.