Here is a page that will guide you on how to get the best ending in Batman: Arkham Knight on PC, PS4 and Xbox One.
Here are all possible ending scenes to Batman: Arkham Knight after playing through the action-adventure’s single-player story campaign, made up of the Main & Side Missions leading up facing Scarecrow and the Riddler to save Gotham City.
Here are the different endings listed in order: • Ending #1: “Bad Ending”
How To Get This Ending: Once the main mission, “Most Wanted: City of Fear” has reached 90% completion, you can receive a bad ending if Batman dies.
The Militia will raid the GCPD building, shooting their way inside. Barbara Gordon is no doubt surprised.
• Ending #2: “Good Ending”
How To Get This Ending: Once 7 of the Most Wanted villains are apprehended and Scarecrow is behind bars at the GCPD Detention Center, Batman can initiate the Knightfall Protocol. This is incomplete, however, as there are still villains left in the city.
• Ending #3: “True Ending”
How To Get The Best Ending: Once all villians are behind bars at GCPD Detention (complete all 14 Most Wanted side missions) — and you’ve locked up all 11 villains and all militia criminals in the city to bring the GCPD at 100% capacity — you can then complete the story by beating the Scarecrow & then Riddler boss fights. Then Batman can activate the Full Knightfall Protocol since Gotham is finally safe. This means 100% game completion. The main villain that is the most time-consuming is The Riddler, since you have to find and solve 243 of his trophies.
True Ending Discussion: Who knows who the dark figure actually is — Azrael or Batman? — the muggers saw the same vision as Scarecrow did when he was injected with fear toxin.
• True Ending Credits: Joker Bonus Song
The Joker, voiced by Mark Hamill, sings the “Look Who’s Laughing Now” song during the credits. This can only be viewed after 100% completion and initiating the Full Nightfall Protocol.
Ending Discussion Note: If you’re going to talk about the game’s ending in the comments section, please put a big fat “SPOILER ALERT” warning text as the first two words before typing your comment. Since comments are highlighted site-wide, and obviously some players haven’t finished the game yet and would like to be surprised.
Credits: Special thanks to XCVii007r1 for the video guides.