As the name suggests, Xanadu is under a chaotic times mainly caused from young Crimson Denizens referred as the Newcomers (新来 Shinrai ) who come from Crimson Realm. These Denizens wreak havoc, devour or kill humans even though the Power of Existence is not needed to be taken from them anymore. Some of them like Brothers of the Maccabee have twisted belief to kill as many humans as they can, believing it to be the God of Guidance's Oracle. The battles between Flame Haze and these Newcomers become inevitable. However, most Denizens who come from the old human world or the Oldtimers (古参 Kosan ) assist their previous nemesis, forming an alliance which effectively helps them to suppress the Newcomers.
On the other hand, human members of Outlaw who were duplicated to Xanadu apparently retain no memories of anything related to the Crimson Realm, resulting them falling into chaos. Later on, Outlaw is reorganized by Flame Haze from the old world and the Orderists (秩序派 Chitsujo-ha ), a group of Crimson Lords who once lost their contractors and now materializes themselves without using human shells.
Some individuals who believe that Humans and Crimson Denizens could coexist in this world continues their long journey to accomplish it; these people include Yūji Sakai and Doog, the survived member of Révolution.
|Character related||Colored Silhouette • Crimson Denizen • Crimson Lord • Crimson God • Faux Vessel • Flame Haze • Kraken • Mystes • Rinne • Servant • Torch • Tuner • Unrestricted Spell Master|
|Conflicts||Ancient War • Sovereign's Game • Great War • Civil War • Révolution War • Second Great War • Chaotic Period|
|Events||Misago Festival • Seishū Festival|
|Items||Crystallization of Self-Research • Treasure Tool • Vessel|
|Creations||Divine Gate • Iron Giant • Statue of Pride|
|Metaphysics||Divine Summoning • Flame • Manifestation • Power of Existence • The Truth of This World • Unrestricted Spell|
|Organizations||Bal Masqué • Brothers of the Maccabee • Hyakki Yakō • Jewel Gang • Minack • Outlaw • Révolution • Töten Glocke|
|Phenomena||Distortion • Faint Heaven Quake|
|World||Crimson Realm • Great Binding Chain • Maelstrom of Warfare • Rift Between Both Worlds • Xanadu|