Rituel
Une créature ciblée gagne +3/+3 jusqu'à la fin du tour et elle doit être bloquée ce tour-ci si possible.
If each creature the defending player controls can't block for any reason (such as being tapped), then the affected creature isn't blocked. If there's a cost associated with blocking the affected creature, the defending player isn't forced to pay that cost, so it doesn't have to be blocked in that case either.