A Tale of Two Villains

My most recent blog post is my idea of an Arkham City sequel. In this sequel, Scarecrow appears as the main antagonist with Hush as the second villain. My question to you is, if you had to pick only one of these two for an Arkham City sequel, who would it be? Who else would make appearances? Would Penguin get his revenge? Would Killer Croc emerge from the sewers? Would Deadshot return? Give your own ideas!