From the eponymous comic book by Patrick Sobral (Éditions Delcourt)

The Legendaries, heroes from the Realm of Alysia, are brave, fearless and indomitable. By fighting the dreadful wizard Darkhell to prevent him from becoming even more powerful and to reign supreme, Danaël, Jadina, Shimy, Gryf and Razzia have accidentally broken the Jovenia Stone, the stone of eternal youth. Every since, all adults from Alaysia and from the Elve world have reverted into childhood… Our heroes are set on breaking the spell and fixing their mistake by finding the Crescia Stone, the only one that will reverse Jovenia’s effect and restore adulthood.