I actually like the Breath Weapon idea, though one could make it more close-range and base it off of claws. You could pick a skill for making attacks with it of course.
For a Breath Weapon, I'd say allow spread attacks and maneuvers and call it Baleful Eye or something. Direct attacks would actually be some unlucky event, like something falling on them, slipping, etc. Maneuvers would be a bad luck curse that could be invoked. To finish it off, toss in the ability to make any inflicted consequence by someone with this ability to become curses themselves. So if you attack with a gun, and inflict a severe consequence, you can choose to instead of inflicting "Belly Wound", you give them "Horrible Luck".*
You could probably make this a -1 ability if you only allow maneuvers and no attacks.
*In game terms you inflict stress as normal. In Narrative terms you perhaps steal luck from your shot (so it essentially misses on a story level), and use that to curse the target.