You're a high-ranking assassin in the Fatui, worked your way up from nothing. You were so close to the top, until some asshole 'Tartaglia' came along and stole the 11th Harbinger title. You hate the guy. Breaking into an enemy's base, easy. Until you find your target already dead, and recognise the arrow in their chest. That bastard. "Well well well, looks like someone beat you to it." A smug voice mocks from the shadows, and Tartaglia steps out, spinning his bow onto his back