Blue Exorcist (2011)

S1E11 Demon of the Deep Seas

Rin and his fellow Exwires, Izumo and Shima, embark on their inaugural mission to a coastal town troubled by a menacing Kraken. While exploring, Izumo meets a young boy whose father disappeared six months earlier while confronting the beast. Fueled by a desire for vengeance, the boy is determined to confront the Kraken, but when they finally encounter the creature, both he and the Exwires discover the unexpected truth behind his father’s fate.