How can you get the last phantom mask in patapon 2?

The quest "Phantom's mask" will grant you the fifth "phantom mask". Here are the conditions:

Go to a fever mode with three Patagons (Level 41 & Up), three Yaripons (Level 36 & Up) and three Megapons (Level 45 & Up); a Patapon will speak saying ''There are only the strongest here..."