This challenge is all about Weapons.
take it literally; excalibur; maybe merlin brings it back. maybe uther never let it go; he kept it, and bad things tore the kingdom apart. what about arthur's sword? maybe morgana has a trusty dagger that's a cold comfort. the dragon has many weapons at his disposal and the way he uses them is bound to bring fear/excitement.
and what of the metaphorical weapons? maybe merlin is a weapon for somebody, something. maybe merlin's a little darker and uses arthur as his weapon, groomed and nourished under a cover of friendship.
weapons; physical, mental, metaphorical. everything and everyone is dangerous. it just depends on how they are used.
You have until January the 30th, 22.00 GMT before the challenge ends and the weapons get sheathed.
pee.ess; if you would like to suggest a challenge for merlin_flashfic, feel free to drop a comment :)