With it being only six months away from Batman V Superman: Dawn Of Justice, there are many questions we have. The main question is: who is Wonder Woman Facing in the trailer.
There has been many fan theories about who will end up being the force which makes Batman, Superman and Wonder Woman team up to stop him. And everyone has gone back to the same conclusion that General Zod's body gets transformed into a monster and the rumour that it's Doomsday keeps popping up but I don't believe that they would use a villain as powerful as Doomsday in a film that won't be able to develop the character since it's a film about Batman vs Superman. So if they were going to have a villain, he has to be powerful and a threat but also make sense with the story.
So I believe it's going to be:
Cyborg Superman as the name suggests is a character which is part cyborg part Superman. Which would seem to make sense with the story that Lex Luther uses General Zod's body and cybernetics to create a superman which he can control. Which Wonder woman, Batman and a weakened Superman (due to kryptonite) have to fight and defeat.
This would make more sense than Doomsday, just because logically, it seems like a lex luther type thing to do, it also could be the reason and how Victor Stone becomes Cyborg