Tony Stark's Anit-Transformer suit
He created this armor when he heard rumors of giant alien robots hiding out on Earth. It was Transformer-sized and made specifically for combat with them. The armor wasn't fully combat-ready at the time it saw action. It had severe energy management issues. Specifically, it was extremely energy intensive and ran low on power quickly. Additionally, it was prone to overload if power was supplied from an outside source. Nevertheless, it served Iron Man well in his confrontation with Decepticons, but was ultimately beheaded by Megatron.
The 14-year-old protagonist of the series. As a child he was prone to crying frequently and, due to his weak personality, was often picked up by bullies, prompting Yajima and Risako to protect him and look after him, thus becoming best friends over the years. This all changed when he acquired, by death nonetheless, the powers of a Factor, though in different circumstances: in the manga he acquired them as a child while forced through an off-limits area in an industrial compound, while in the anime he was already a middle-schooler, shortcutting through a shrine to come back to school in time. In both instances, his future Machina Linebarrel, literally crash-landed on top of him and, sensing his life ending, revived him and linked with his life force. This endowed Koichi with super-human physical abilities, yet it also made him very arrogant, prideful and overconfident, so much so that he himself became the actual gang leader of those who used to bully him.
Luthor obtained a specially made warsuit built on Apokolips and used it when his plan to blame Superman for a falling Kryptonite meteor failed. The suit made him even with Supermans abilities.