Mr. Freeze would be an awesome villain for The Batman 2.
Mr. Freeze has so far only appeared once in a Batman movie. This is a shame given how deeply complex the villain is as a character in the DC Universe! I loved how grounded The Batman was, how everything was very realistic, even possible in modern day to an extent. Even the Batmobile wasn't over-the-top, it was just a dope regular car. Imagine a Mr. Freeze in this same style of Gotham, who like, stuffs people in freezers or something, lol.