By that logic, if Cthulhu rises from the ocean and walks into New York, you should try to fly by jumping off a building, because a supernatural being exists, and the things like gravity couldn't possibly still govern us.
I hate seeing absurd logic like this. Reality still exists. Quantum mechanics, physics, gravity, all still exist. Being able to shoot fire from your hands does not mean that the laws and rules of reality don't exist, it just means you, or whatever character or creature, can bend them.