Fidio's Intense Friendship Training!

Fideo appears again, telling Endou to fight him and his team with all his power, and tells Endou that he will help him finding the key to complete his new hissatsu. He does this to help Inazuma Japan to win against Cotarl's nationals Little Gigant.
What is Fideo up to? And what is with the weird formation of Orpheus? And why cannot Endou stop any of the moves? Will Endou be able to complete his new Hissatsu?