Mr. Freeze
In the alternate timeline of "Flashpoint", Mr. Freeze attacks the S.T.A.R. Labs in Central City to find a cure for his wife Nora. However, Citizen Cold attacks and uses his cold gun to freeze Mr. Freeze's body. Mr. Freeze tries to escape on robotic legs, but Citizen Cold freezes him to death and tells him that Nora is dead. This version of Mr. Freeze is a friend of Fallout's and pursues revenge against Citizen Cold for murdering him. It is later revealed that radiation produced by Fallout is the cure Mr. Freeze was searching for.