OOC: In-Play Mechanics
I want it to be something that burns/impairs rather than just a straight damage buff? I'm not 100% sure if this is within the rules, but ideally I'd want something that I could stab someone with, create the Aspect, and then Invoke it to inflict a -2 on an action they are taking as the magical poison burns through their veins (with Fate points spent if I want to Invoke it more than once).
Ah, I was reading it as a damage bonus!
I did a little quick reading about modelling poisons using fate core. And overwhelmingly, I see suggestions for extending the fate fractal to the poison itself. So, how about this:
Mindfire Poison
Aspects: Magical in Origin, Contact Poison, Responds to heat-treatments
Stress: [1][2][3][4][5]
Skills: Headache(+3), Resist Treatment(+2)
If an attack with these poisoned blades succeeds enough to inflict stress (making it a contact poison), you force the condition Poisoned By Mindfire on your target. Each round, thereafter, the target must defend with Will vs a Fair(+2) rating to avoid taking additional Mental stress. Each attack costs the MindFire Poison 1 stress.
After the scene in which the poison is inflicted ends, the MindFire Poison will attack a number of times equal to it's remaining stress-track before the next sunrise. Once the stress-track is used up, the poison will have burned itself out.
The target Aspect, Poisoned By Mindfire can be invoked to your direct advantage, as per Create Advantage rules. The poison on the blade lies dormant until inflicted, or until the next sunrise.
To my mind, a greater success on the Lore role that created this magical poison would then allow the strength of the poison's attack role to also scale up... so you could, in fact, have poisons with a +3, +5 or greater attack roll.
This message was last edited by the GM at 17:00, Sun 19 Apr 2020.