Akane Sawatari

Akane Sawatari deserves most of the credit for the high energy of the series' final episodes. Her pact with the Snake Devil makes her difficult to deal with, despite the fact that she appears to be a carefree adolescent with hardly any powers. However, her tale was concluded in the first season, so we won't get to see her again in future installments.

Akane has the ability to call forth the Snake Devil at any time, and the Devil will then attack the adversary at her bidding. Example: If you tell the Snake Devil to "Swallow it all," it will eat the entire thing. Also, if she orders, "Spit it out," the Devil to expel the enemy, the Devil will be forced to return them to the fight on Akane's side.