I'm curious if people have found this to be worth it? 3 fate is costly, and you need to make sure you can handle taking fate off your own characters to. But a heavy control deck with this and Waning Hostilities could really annoy some decks.

It is either a card you want to build your deck around, or a card that you play as a singleton for the surprise factor. The effect is very powerful and also very situational.

The places where I tried it in was in a heavy event driven unicorn deck that is trying to resolve cavalry reserves. You try to make this affordable and somewhat reliable by splashing phoenix for display of power so that you can contest the imperial favor. You play shinjo scout plus windswept yurt in order to hoard fate.  Mono no Aware is your tool against decks that try to keep characters in play. With cavalry reserve you have a greater ability to get back on board with a province break from almost nothing in play. While I think the concept might work, currently unicorn does not have the dynasty character set that would really enable this plan.

The other place was in crane with kakita yoshi for potential discounts. You play this together with silver-tongued magistrate as the 4th and 5th copy of consumed by five fires (jank warning!). This combination makes it trivial to break a province, though the set-up cost is pretty extreme. You also need to play a larger contingent of shugenjas to try this plan. In the games in which I tried this, it worked well, but I usually already won way before I pulled off this combo.

In conclusion: I have found edge cases for it. I think it is a reasonable card to play as a one-off in your go-wide decks.

Maybe in a City of Lies deck? Would seem to synergise well with Scorpion conflict denial.

As if scorpion needed more ways to make opponents feel miserable.