The Apex System: My Army of Mecha Queens

Quentin Lox transmigrates into a mecha girl world but is betrayed due to his F-rank talent. To make things worse, he risks losing his inheritance to greedy relatives. He awakens the Apex Upgrade System and transforms a dying E-rank mecha girl into an SSS-rank one. He reclaims what is his by winning a match. Then, he uncovers the conspiracy of a cult called the Mechanicus. With his powerful mecha girls, Quentin rises and becomes a force to be reckoned with.