I was thinking that a single-shot dueling pistol game could be a decent theme for this "you only get one" challenge: a race between speed and accuracy to hit a target before he hits you, with a tally of wins vs losses at the end.
You could maybe even set up such a game in SoM by using limited MP with the Light Arrow spell to make a "single shot", and using invisible barriers to lock the player in place so he can't dodge bullets. Would be interesting to try anyways 
You could maybe even set up such a game in SoM by using limited MP with the Light Arrow spell to make a "single shot", and using invisible barriers to lock the player in place so he can't dodge bullets. Would be interesting to try anyways