Arknights (page 4)
Integrated Strategies #2: Phantom & Crimson Solitaire, often simply known as Integrated Strategies 2 (IS2) or Phantom and Crimson Solitaire (Crimson Solitaire or PCS for short), is the second season of the namesake roguelike game mode in Arknights.
Crimson Solitaire introduces new mechanics that becomes the future standard of I.S., notably the fact that the game mode is now permanently available, as opposed to the first tentative iteration of I.S. in Ceobe’s Fungimist which lasted three weeks.
Phantom & Crimson Solitaire focuses on a macabre adventure experienced by Rhodes Island after they entered a seemingly abandoned castle in Calais-Blason, Victoria (formerly Gaul) as part of a search-and-rescue mission for the missing Phantom.
The R.I. operative Phantom went missing sometime after he was reminded of his past as a member of “the Troupe” and head to his supposed birthplace Calais-Blason. Upon hearing the news, the Doctor assembled a team of R.I. operatives which includes Phantom’s colleague Shalem and sent them to Calais-Blason to find Phantom.
During their trek through Calais-Blason, a dense fog forces R.I. to find shelter as night falls, arriving at the doorstep of an old castle.
Inside the castle, R.I. quickly finds out that it contains many strange rooms that did not follow a fixed pattern. Further investigation indicates that the castle now acts as the base of Crimson Troupe, a theatre troupe dedicated to follow the twisted wishes of its enigmatic leader and is used as a “stage” for their dastardly “plays” driving many who entered before the team into insanity, if not despair and eventual tragic deaths.
…It is implied that most of the events in the castle are illusions taken from the explorers’ experiences, which can explain why most of the enemies encountered are first seen in prior events. This also includes W’s presence, even though she is nominally part of R.I. and are in Victoria at the time.
All four Phantom & Crimson Solitaire endings are canon and forms a connected story, but whether they are canon to the main Arknights storyline as well remains unknown.