Lei Che was an ordinary human, but his peaceful life was shattered when Destrudos ravaged Earth, killing his mother in the disaster. By an unexpected twist of fate, he is reborn as the monster Red King and bound to an Infinite Evolution System.
In a world protected by Ultraman and plagued by monsters, humanity sees him as an enemy, and Ultraman Zeta attacks him as well. Meanwhile, a mysterious dark force from outer space schemes in secret, sending mechanical beasts and an army of shadows to collect energy and resurrect the evil Alien Empera.
Lei Che struggles to survive against all odds, constantly evolving with the abilities granted by the System. He devours monster remains to gain evolution points and unlocks amazing skills such as taking on a human form and countering energy attacks. As he fights alongside Haruki Natsukawa against the forces of darkness, a shocking secret gradually comes to light: his rebirth seems to be a crucial part of the dark forces' plot, and behind it all lies a tangled connection to his mother's death.
