  Continuing our previous work, we determine a minimal left characteristic
biset $X$ for every exotic fusion system $\mathcal{F}$ on the extraspecial
group $S$ of order $7^3$ and exponent $7$ discovered by Ruiz and Viruel, and
analyze the finite group $G$ obtained from $X$ which realizes $\mathcal{F}$ as
the full subcategory of the $7$-fusion system of $G$. In particular, we obtain
an upper bound for the exoticity index for $\mathcal{F}$.
