Union Academy (except for those who redeemed themselves and left the academy)

Legion of Doom (Vandal Savage, Deathstroke, Sinestro, Reverse Flash, Cheetah, Doctor Sivana, Maxima and Ocean Master)

Note: Vandal Savage will be the main antagonist of Season 2

Emerald Sustrai (she will steal Batman's contingency plan for Vandal Savage)

Loki (Season 3 Antagonist)

Oscar Pine/Doomsday (Ozpin will inject Doomsday's DNA on him, making him the last resort weapon.)

Crime Syndicate (Season 4 Antagonists)

League of Villains

Salem (One of the Final Antagonists)

Darkseid (One of the Final Antagonists)

Thanos (One of the Final Antagonists)

Notes: Salem, Thanos and Darkseid will make a ultimate alliance to try to conquer the earth, and this will lead all heroes to face the trio in the final battle.