Support your child and help him to believe that he is capable of performing miracles no less than Santa. I think that in such situations, the desire for self-expression suffers most of all, since the child begins to close off from classmates who tease him, but doesn't understand the reason for this. Perhaps some kind of hobby will help you cope with this, which will contribute to the fact that your child will begin to perceive magic, a fairy tale, miracles a little differently. For example, you can teach him to show tricks. Here is Free Tricks To Get Started
. I've only watched a few videos, but it really shouldn't be too hard.