Arkham went out with a bang in Arkham Knight, however here are 5 DC characters Rocksteady could focus on next after a well deserved break. (And no the Justice League is not included)
Superman is the most obvious choice to success Batman. With a mountain of possibilities, however, one would be another elaborate plot by Lex Luthor to rid the world of Superman. Superman could have kryptonite which drains him of all powers bar flying and heat vision.
Green Lantern is a very intriguing possibility. This is because he has a huge villain in the form of Sinestro. As is very obvious, he is a dark, twisted reflection of John. This game could focus on another of Sinestro's plots to harness the power of the green ring and take over the world. The ring could be low on energy and with each mission completed, the ring gains more power. When a certain amount of power is in the ring, a new shape can be available in the ring.
Nightwing, despite being an ally in Arkham Knight, could have his own spin off series with him protecting Blüdhaven against the threat of Deathstroke, who has been employed by an unknown man who wants Grayson dead. Deathstroke draws Nightwing out by owning his own militia. These take hostages which threaten to kill them. Nightwing eventually has a huge boss fight with Slade to finish the game.
Deathstroke may be an assassin, but that doesn't mean he can't have a video game. OK, now the boss battle wasn't great in Arkham Knight, but he is still a great character. Deathstroke could be on the run from Amanda Waller after ditching the Suicide Squad. Each boss battle would be against a different person from the squad. With Rocksteady utilising guns for the Red Hood DLC, the game could involve his two handguns. This could be a great game.
Speaking of the introduction of guns..... Red Hood is a hell of a character. With his knife, his dual handuns and his zip kick, Red Hood could be even more dangerous than Batman himself. The story could be him trying to stop another of Ra's All Ghul's elaborate plots to rid Gotham of evil once and for all. However, Red Hood could be one of the people with the Joker infection, but he recieves the symptoms later than everyone. Whilst battling with insanity, he must stop Ra's Al Ghul before he finishes Gotham off for good.
These are my five DC characters I feel Rocksteady should focus after [Batman: Arkham Knight](tag:2683936). If you feel I missed anyone please comment below.