Peace Talks has a flaming ward circle, with we are told (i) massively increases the power of the spells cast in it, (ii) is highly erratic, and (iii) is considered close to Law Breaking by the Wardens.
My thought on how to rule this:
- while using the circle, the Wizard has Sponsored Magic[Fire]. If this drops his refresh below zero: tough, he's an NPC* until the circle is destroyed. However, the magic is correspondingly more powerful.
To reflect the erratic nature, I'd also say that each Circle is slightly different, granting a slightly different 'flavour' of Fire Magic. So initially the wizard isn't going to know what the circle is going to do. Of course, he could just maintain the Circle permanently - in which case he has Sponsored Magic[Fire] all the time, and there is no deed for the magic to be erratic.
*"Fire pretty, Tree Bad" as a new personality type would explain why the Wardens stomp on this.