Xan's the star of a TV pilot I wrote a few years ago (fingers crossed, it's making the rounds in Hollywood.) His story's been adjusted for the Arkham Horror universe (replacing my own similar-ish organization with The Agency, having his main story take place in the '20s instead of the present).
Xan's gameplay is all about SOLITUDE. He's a deeply troubled individual who fears the consequences of losing control over his simpleminded, conjoined extradimensional twin, Et. When that happens, Xan's body transforms (as seen in the portrait lifted from the Call of Cthulhu "Wizard of Yog-Sothoth" card) and Et goes on a rampage like the Incredible Hulk, attacking friend and foe alike until Xan regains control. Xan abhors violence and as such cannot use Weapon cards. He's also useless at combat and clumsy as hell, which he makes up for with a combination of Et''s ability to "retaliate" against enemies and his free "teleport" action.
As a son of Yog-Sothoth, Xan has the ability to open the way for the Old Ones to awaken. Nyarlathotep will stop at nothing to make him sign the Book of Azathoth and seal this fate. This is reflected by his inability to go insane, instead adding doom to his personal weakness whenever he takes horror, which can advance the agenda and cause the Investigators to fail the scenario outright!
And as a time traveler, Xan has naturally attracted the attention of the Hounds of Tindalos. Note that this is a basic weakness, not a personal one, that happens to be selected specifically instead of randomly. When drawn, it spawns from the location furthest from you and then hunts you down without mercy, building up unavoidable horror as it stalks you relentlessly. Xan can take the incredibly risky option of allowing it to push him to his horror threshold and then unleashing Et's flip side, but at what cost?





