The Final Battle

Riddick knows he is severely overmatched here by the holy half-dead lord marshall and so he's trying to end it quickly and sneakily you know first with that big a flying attack and then he throws a knife at him later on. Ultimately riddick pulls off a lucky death below because as vaco is coming to execute the lord marshall  to claim the throne for himself lord marshall does his shadow teleport thing out of the way to grab a weapon, where riddick is. He does a cool kill maneuver where he stabs into the top of the head with the blade and snaps it down.