I, the Sub-Species Empty Me, Choose One of the Three at the Beginning

Yu Natsukawa, an ordinary college student, accidentally put on a defective Kuga belt that had never been recorded in a dusty super-ancient ruins. The posture after transformation is not red, but black, which symbolizes ominousness. His strength, speed, and senses are all weaker than that of the legendary warrior. However, crisis is also a turning point! Whenever he kills an unconfirmed life form, he can gain experience, and when upgrading, he can choose one of three [Linduo Runes] to strengthen himself! [Chain Lightning]: The attack comes with ejection lightning, a magical skill to clean up miscellaneous soldiers! [Unyielding Will]: Locks blood for three seconds when dying, essential for counterattack! [Power of Sublimation]: Sacrifice your current form and get the ultimate form experience card for your next transformation! Facing the weirdos from other (Kamen Rider) worlds, he will start from the weakest subspecies, Kuuga, and make choices step by step, heading towards an infinite path of evolution that no one has ever stepped on! He wants to use these black fists to protect his own smile!