Which Rocksteady collection was remastered by Virtuos?

Batman: Return to Arkham was the Rocksteady collection remastered by Virtuos.

Released in 2016, Return to Arkham bundled remastered versions of Batman: Arkham Asylum and Batman: Arkham City. Virtuos rebuilt the collection for PlayStation 4 and Xbox One using Unreal Engine 4, replacing the original releases’ Unreal Engine 3 presentation with updated models, environments, lighting, effects, and shaders.

The package also included the previously released downloadable content for both games. That meant the collection combined the Game of the Year-style bonus content from Arkham Asylum with Arkham City’s additional material, including the Harley Quinn’s Revenge story expansion and extra character and costume content.

A frequent confusion is Batman: Arkham Trilogy, which contains Arkham Asylum, Arkham City, and Arkham Knight in a later Nintendo Switch release. It was not the Virtuos collection in this question. Arkham Origins was also excluded from Return to Arkham, so the collection covers the two Rocksteady-developed games that preceded Arkham Knight rather than the entire series.