I'm no one

Oh, because it wasn't at the end of The Headless Star, but at the end of episode 21.5! (Which wasn't actually an episode, but a "lookback" interlude that summarized everything that happened between episodes 14 and 21).

Although the poem was revealed earlier, as the official site posts a phone wallpaper with each week's respective poem, and they posted Gigi's sometime after episode 21 and before episode 21.5 aired:

“I'll come back for ya'!”

(Thanks to my notifications I suddenly remembered this old Rizna x Looney Tunes meme I made.) It's okay Riz, he'll come back to visit you again soon.

Reference:

I've been thinking about Giselle's poem all week because it truly seems like one of the simplest poems in the series, but at the same time it is very smart and perfectly fits her?

Starting with the fact that the word used for love here means "liking someone (romantically)" or "being in love with"; but it's also a word for "lustful", a play on Gigi's weird attitude towards Bambietta (sometimes hugging her & telling her that she loves her and other times just enjoying her zombie state too much).

And the second verse, "To death" is the same as in English, meaning "so much/like crazy", and not meant to be taken literally. But of course, the joke here is that Gigi surely means it quite literally...