User blog comment:LastationLover5000/Fairy Tail 307 - In Which My Favorite Kitty Is Alive (Garou Knights)/@comment-3030647-20121109234154/@comment-4728047-20121109234945

i'm not sure it counts as emotion, but when one's life is in danger they tend to get an adrenaline rush which has been known to increase one's strength to near superhuman levels, again not sure that really counts but that could be the idea behind it