MC gets reborn in My Hero Academia as a twin brother of Momo Yaoyorozu born with a quirk that generates endless nanites inside his body and has the ability to control said nanites at will, allowing him to generate various machinery from his body. He can also use his nanites to communicate with a variety of machines.
MC's Abilities:
Machine Manifestation - MC can shape his nanites into a variety of machinery. He uses these for offense, defense, and transportation. The weapons he forms out of his body can be destroyed, but he usually can reform them quickly afterward. Also, if he is exhausted, it takes more focus to maintain his weapons; otherwise, they instantly disassemble.
Technopathy - MC is capable of using his nanites to interface with technology, allowing him to communicate with and control it.
Healing Factor and Hyper Adaptability - Nanites will have a variety of both direct and passive defense mechanisms for him in and out of combat.
Infinite Nanite Supply - MC has a self-replicating program, meaning that way he can create more and more active nanites if needed.
*MC has Rex Salazar's Power as a Quirk
*MC love interest would be either Mei Hatsume or Melissa Shield.