Pretty self-explanatory, you click the shout/cast spell or whatever button, and your character breathes fiuh just like the dragon in the trailer. Enemies that cannot stand the initial hit will be burned to ash and others will catch fire for a few seconds, running around and dropping to the floor. The ground will catch fire just like the trailer and it will drain all of your magic and stamina.
Initial damage would be based on your stamina (because it takes effort to do the shout) and length and severity of the after-burn will be based on magic (I guess because the fire is magical. This game has elves and dragons, do I really need to make up a logical explaination?)
Just a random Idea I thought of. Feel free to flame me, (cwutididthar?) make suggestions or whatever, but this is just a joke thread anyway