Series Name: The Demon Sword Master of Excalibur Academy, Vol. 1
One of the most powerful demon lords in history has been sealed away for a thousand years. When he finally awakens, he is reincarnated as...a 10-year-old boy?! Now under the care of the girl who released him, the demon lord Leonis must navigate the perils of Excalibur Academy!
https://www.amazon.com/Demon-Sword-Master-Excalibur-Academy-ebook/dp/B084MDD44V/ref=sr_1_2?_encoding=UTF8&keywords=9781975308667&qid=1581464223&s=books&sr=1-2
One of the most powerful demon lords in history has been sealed away for a thousand years. When he finally awakens, he is reincarnated as...a 10-year-old boy?! Now under the care of the girl who released him, the demon lord Leonis must navigate the perils of Excalibur Academy!
https://www.amazon.com/Demon-Sword-Master-Excalibur-Academy-ebook/dp/B084MDD44V/ref=sr_1_2?_encoding=UTF8&keywords=9781975308667&qid=1581464223&s=books&sr=1-2