Supercharacter theories for Sylow $p$-subgroups of Lie type $G_2$

We construct a supercharacter theory, and establish the supercharacter table for Sylow $p$-subgroups $G_2^{syl}(q)$ of the Chevalley groups $G_2(q)$ of Lie type $G_2$ when $p>2$. Then we calculate the conjugacy classes, determine the complex irreducible characters by Clifford theory, and obtain the character tables for $G_2^{syl}(q)$ when $p>3$.