Hayder

Involvement
He is one of the henchmen of Castillion, the former employer of Isabela, and has been sent to forcibly inquire about the location of the relic. A duel between the two is arranged though he attempts to ambush her, setting Isabela's recruitment quest, Fools Rush In, in motion.

Result
He is confronted in the Kirkwall Chantry by Hawke's group and Isabela, where it is possible to inquire as to why he is after the former pirate captain. In the end he is killed

Those that play the demo released on Feb 22, 2011 can presumably "loot" his sword Hayder's Razor for the full game via DLC.