Charlotte does not like to be tied and will always maintain that position. However, she is easily subdued so long as her magic book is taken away from her. Since she wears a miniskirt with thighhighs, it's best to leave the skirt untouched to allow it to sway and grant more glimpses of exposed skin while struggling for a more titillating experience rather than simply using a shibari. She will not settle down until she gets tired, so it's best to tie her heavily and keep clear of kicks, headbutts and other attacks unless she's secured to something. She can still cast spells even without her books, so keep her effectively gagged and do so quickly.