This story is a sequel to Une autre transformation d'anniversaire

Jimmy's birthday has decided to keep him busy. Not just content with changing him into a French version of Chrysalis, it makes sense that the City of Love should play host to the Princess of Love herself.

Or, rather, a Cadence from an alternate universe...

One of several birthday presents for JimmyHook19.

Note about spelling; I'm from the UK, and as such spell the name 'Cadence' with an 'E'.