I like the card itself. It fits fire from a roleplay point of view, but with deflagration, fire already has a counter to shields or sundials. Id rather see it as a life card, where it would fit both from a RP perspective as well as from balancing. Would be a bit sad about the name though, its great for a fire card. :p
One more thing: The benefit from upgrading this card is too high. +2 instead of +1 is already quite a huge boost, it really shouldn't become cheaper aswell.