|It's a good thing Arkham Knight's gonna be the last game. I don't|
wanna know how much dirtier Riddler could get.
Riddler Trophies and Puzzles: This one is pretty much confirmed since, as you can see from the above picture, Riddler is confirmed to return. I would think that it would be about the same as in the previous Arkham games, just with the amount properly adjusted for the scale of the game. Maybe it could end with one final confrontation with the Riddler, and hopefully he could reveal that "big secret" he teased in Arkham Origins.
Return of Hush: Considering that Hush was featured in a sidequest in Arkham City, it would only make sense to follow up on that in this game. Maybe he could run around the city disguised as Bruce Wayne, causing trouble. Batman would have multiple encounters with him, or have to track him down again, and this time, put and end to Hush's schemes.
Halloween Killings: This game is taking place on Halloween, and the holiday themed Calendar Man has made appearances in City and Origins, so I think it's time to see firsthand what he can do. Obviously, going from the name, you would have to track him from murder victims, possibly overdressed for Halloween. I would imagine that if you do fight him, it would be a Predator encounter, similar to Two-Face at the end of the Catwoman DLC for Arkham City, or Deadshot in Arkham Origins. It makes sense to me.
The Ventriloquist & Scarface: While Scarface made appearances in Asylum and City, the Ventriloquist never actually showed up, and I think his appearance is long overdue at this point. I envision that this would work similar to the Zsasz sidequest from Arkham City, with Scarface "holding Ventriloquist hostage" and you having to get to certain locations before he offs him. This would be assuming that Ventriloquist doesn't believe he's in control of the puppet, that is.
Other Batman villains who have been referenced getting their own sidequests: Yeah, I got nothing else at this point.
So there you have it. Those are just some possibilities of sidequests I feel could make it into Arkham Knight. Only time will tell if any of them are actual sidequests in the game.
HBM, signing out.