Sylvette has green hair. This is a sign of the Laplace factor. That's why she can cast magic without a spell. It means that it is impossible for people who do not have the Laplace factor.
Tip to improve. Don't make the hero a pervert like Rhodeus and try to give him one or two girls at the most because the more girls the more rubbish.š
And she's on a good track so farš„°