What fire thing are you talking about? The Solar Flare?

You find it on the Ezofuji (sp?) mountains. In front of this ice machine thingy that's blowing out snow. If you look to the right, you can see a wall with a space you can blow up. Use cherry bomb, and go downstairs. I would suggest dealing with the tree, and then using galestorm to blow away the leaves. The illustration beneath shows the direction that you need to stop the spinning wheels on the machine at to break the machine. Once you've gotten the directions down, go to the machine and at the side you'll see a little handle thing. Slow down time so you can pinpoint when to stop the first wheel at the correct point, and then power slash the handle thing. Repeat until the machine is broken, and then a constellation will appear and the final god will give you the Solar Flare.