This week’s challenge has a bad translation in French.
It is saying : Win 15 fights using only 5 heroes (Gagnez 15 batailles en n’utilisant que 5 héros)
What it should say / what the quest really is :
Win 15 fights using less than 5 heroes,
It would translate to : Gagnez 15 batailles en utilisant moins de 5 héros.
It is a bit confusing