You can buy some cotton fabric that is patterned to look like fire, but I presume you're going to make it look like you're bending it, so that might not be the best choice.
Most likely, you'll want to bunch up red and orange sheers. Tulle will probably be a good choice, since it gives a lot of volume, but mixing some organza in could potentially work as well.
DeviantART // Tumblr // Facebook
- Suzuha Amane (Steins;Gate): 95% (Final Details) Katsucon 2015
- Magic Armor Link (LoZ: Twilight Princess): 22% (Patterning) Katsucon 2015
- Human Beatrice (Over the Garden Wall): 29% (Sewing) Katsucon 2015
- Emperor Lelouch (Code Geass): 2% (Planning) Spring 2015