A brief description of the I’m Just a Human but Was Raised by the Four Heavenly Kings of the Demon Lord’s Army; the Demon Lord’s Daughter Loves Me and Bestowed Upon Me the Authority to Rule Over All Attributes manga:
The main character, Leon, was thrown into the world of demons immediately after his birth because of his lack of magical power. However, his fate changed dramatically when four Heavenly Demon King of the Army picked him up. The four Heavenly King, the strongest and most powerful figures in the world. They personally trained him and took good care of him.
Over time, the boy became a magnificent soldier of the Demon King’s army, having the power to “control” all kinds of elements.
Leon received a new mission to protect Alicia, who enters the Magical Academy on the island called “Paradise Island”.