The singular "star" can only be accepted by people who can't read in a holistic way.
Surely makes lots of sense that Marco is speaking in singular even though the whole page is sending a plural message, from Zoro and Sanji attacking together to the "The Wings appear!" editor's note.
This is Toei butchering the original material; which, again, isn't new for anybody knowing the amount of mistakes they've made through the years.