(CNN) After Rio de Janeiro's evangelical mayor tried to ban an illustration of two male superheroes kissing from a book fair, one of Brazil's biggest newspapers decided to put it on their front page.

The controversy kicked off last week after Rio Mayor Marcelo Crivella demanded that the Marvel comic book "Vingadores: A Cruzada Das Crianças" ("Avengers: The Children's Crusade") be withdrawn from sale at Rio's biennial book fair because it shows male superheroes Wiccan and Hulkling kissing. The book was completely sold out at the book fair by Friday, organizers told Agence France-Presse.

The Folha De Sao Paulo newspaper said it used its Saturday front page and Sunday editorials to discuss the issue.

"The mission of professional journalism and a newspaper like Folha is to be uncompromising with obscurantist attempts and to shed light on threats of censorship," said Sérgio Dávila, the paper's editorial director.

The book was initially published in 2010. Its illustrator, Jim Cheung, said in a lengthy post on Instagram that the debacle "is now being drawn into the spotlight by the mayor perhaps only highlights how out of touch he might be with the current times."