IMO, it'd be a lot more fun to kick that limping bandit chief onto his back before plunging a sword into his neck. Instead, I just whack him and he falls over.
Anyways, do executions exist? Or just finishers?
EDIT: I had a cool execution yesterday with dual swords where I put a bandit chief on her knees before crossing my swords through her neck. I was all "=O...=D" It'd be neat to do that when enemies are "down but not out", too.