In order to go to the treasure chamber together with his friends, Yuno confronts Mars alongside Klaus, so that the injured Mimosa can heal herself. But they have a hard time harming Mars at all.
After all, I've fought far 
more mages than you have.
durch meine vielen Kämpfe
mit anderen Magiern besitze.
visto che io ho combattuto molti più maghi di te.