I'm now up to two dead Justice League members. At this point, it is important to add that Wonder woman didn't get sucked into Braniacs plot, so she's still on the side of the "good guys".
Each character has beef with one super hero and they literally say it before you get into the fight. You can use any character you want but the game is designed to make it easier when you use the character with beef with the justice League member.
In this battle, I used Dead shot because of his long standing beef with Green Lantern. The dialogue between them shows serious animosity between the two.
It's pretty ironic that the good guys in this game series are only good guys because they're trying to kill the villains that were in fact the good guys that foiled their multiple attempts at crime.
At the end of this arch, Wonder woman was murdered by Superman, despite plunging a sharp block of kryptonite into his chest. It seems Braniac's mind control reduces his susceptibility to the element from his home planet.
We saw Harley Quinn show an emotional side towards Wonder woman, indicating that she's probably going to be psyched up to carry out Superman's murder. We're probably going to get some kryptonite infused weapons from Gizmo that enables us face Clark Kent.
Then again, Harley Quinn has history with Batman in Gotham City, so it is possible that she's psyched up to fight him.
Anyway, I have a feeling the final villain will be Batman. We already encountered him once and he put us all on our arses at the same time. His greatest asset is his ability to mastermind plans and I reckon he will be a very difficult boss battle.