>>80982680Toffee threatened to kill Marco with a slowly-shrinking force-field box if Star didn't do what he said, and when she surrendered and handed over the wand, he said that he didn't want her to give it to him, he wanted her to destroy it. So Star used the whispering spell to destroy the wand. Turns out the wand self-destructs like a bomb when that happens, so Star sealed herself in the box with Marco while the wand self-destructed and blew Toffee to pieces, leaving behind only a finger.
It's in the episode.