Man of Iron (Highschool DxD)

Andrew Stark, son of Edward Stark, is on the fancier side of life. However, his legacy comes from his father, who unfortunately passed away when he was fifteen. During his takedown of his closest friend Obadiah Stane, he figured he'd move to Japan, a small town preferably. He found Kuoh, a small quaint town with a few thousand people.

Here's the interesting part; before that could happen, Andrew was kidnapped and held prisoner. He was hit with a missile of his own company, sending shrapnel into his body. He was saved by a man called Yinsen, hooking a car battery to a powerful magnet. They survived for three months in a cave of the captors before creating a suit. A suit of armor that Andrew was going to don.

But, there's a twist. Andrew was never this smart. He was a genius, yes, but his intellect almost tripled because; in that cave, he found an etching into a wall. It was indecipherable and inexplicably complicated for it to be cavemen. When he touched it, the art glowed red and gold before disappearing.

Now, after going to Kuoh, he decided to continue his hobby of building suits and handling business; Unfortunately, his caretaker, Emmylou 'Friday' Richings, his maid yet parental figure, signed him up for school. Wonder what's gonna happen here...