I've had an idea pertaining to 'Emotion' that I think is rather cool.
(disclaimer: using this idea will not make me score you higher than if you'd used any other idea of equal quality)
Say you're a totally badass Samurai (Samurai Jack level of badass-ness). Your weapons are as much your clarity of thought and your perception as much as your sword. To be at your most skilled, your most deadly, you must seek to control your emotions, to have them guide and support you instead of distract you.
So, as the player, what you get control over is the character's mind (possibly the fight as well - I'm not sure). You have to control what he thinks about. Different thoughts have different emotional charges associateed with them - for example, thinking about the bad guy or the village his henchmen burnt down would make your character more angry, which would increase the force used in his attacks but lose accuracy and manouverability. Thinking of long ordeals already survived might give him more determination, improving his blocking ability. Thinking of that pretty girl in the last village causes him to be distracted, to react slower to the enemy.
Thoughts would keep shifting and moving; some would exercise 'gravity,' pulling themselves into focus, while others would try to resist being brought to light (when angry, it might become more difficult to think of things that would calm you down). It's possible that you'd even be able to control the actions of the fight itself through this 'mind control' interface, by thinking about different attack techniques or different actions. You think about the enemy's legs, your character tries to take them out from under him. You think about being far away, your character takes some steps back.