Golden Dragon: Six Thousand Years of Empire - Chapter 6 Causation

[Across the Stunning Beast Princess: Phoenix Against the World]

She, First Princess residence’s only legal daughter, yet known as a waste throughout the whole country!

When her cold eyes opened, she is the 21st Century’s most dangerous genius assassin!

When the sickly young miss exposes an edge, she is absolutely brilliant, and countless men and women in the world greatly admire her……

He is the absolute king of the night, cold blooded and ruthless. In troubled times, he by chance meets her, a zither and flute ensemble, since then in heaven and earth, life and death go hand in hand.

- Description from Novelupdates

In a world where all magical spells have been captured into cards, those who can build a deck have the most power.The most Arthur could ever hope for was to someday earn a trash-tier spell card. When fate grants him a legendary Master of Skills card, he's thrust into a world of opportunity and danger.To survive and grow strong, Arthur must learn skills. All the skills.

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?

Having the capability to destroy humans, elementals, and gods, after a long period of countless wars and strife, Arnos the demon lord became sick and tired of all that and longed for a peaceful world, so he decided to reincarnate to the future.

However, what awaited him after his reincarnation is a world too used to peace that his descendants became too weak due to a huge weakening in magical powers.

Arnos enrolled in the Maou Academy established to find any students that might be the demon lord’s reincarnation, but his powers are too extraordinary that those in the academy couldn’t properly judge his powers, so he’s regarded as an “Inept student”. Being underestimated and avoided by most people there, he recruited a girl friendly to him, Misha, as his subordinate and comrade, and strives to climb to the top of the demon race hierarchy to one day reclaim his former title and status.