He doesn't see the feint coming, but he also doesn't get more than a couple steps past the demon before spinning around to correct his course. His sword follows through the same arc, aimed for its shoulder.

(Clumsily; he's stumbling a little. Alistair's lost all finesse Warden training might have offered. He doesn't care how he fells the enemy, just that it happens, just that he stays upright and keeps fighting.)