In the upcoming 2nd half of S2 of Gotham, Mister Freeze aka Victor Fries barges onto the scene icing literally everything in his path. He has indirectly kidnapped Silver St Cloud daughter of a deceased crime lord. Gordon must unite GCPD to stop and foil Freeze and rescue St Cloud, whereas another villain, Dr. Hugo Strange, played by OUAT's Robert Carlyle, serves as the Season 2B secondary antagonist. The main antagonist of S2 overall is The Penguin.
Mr. Freeze puts Gotham literally on ice late Feb 2016 on Fox.