Transmigration + multiple heroines + System + crossovers with other Ultraman heroes + monster battles
Overworked office worker Lin Chen transmigrates by accident and merges with the light of Ultraman Nexus. Bound to the Myriad Worlds Ultraman System, he starts in his childhood form, aiming to attain the legendary form of Noah.
The Space Beasts' roars tear across the city skyline. He transforms into a crimson-and-silver figure and fights his first battle, unaware that Nagi Saijo, the Night Raiders' deputy captain, has her eye on him. He must conceal his identity while living among humans and wield the power of light against the darkness. What he never expected was that fate would draw one unique girl after another into his battles and his life.
The passion of the Showa era, the bonds of the Heisei era, the brilliance of the New Generation, and even the legends of the Mysterious Four Ultras: his arrival will stir up a different kind of turmoil across this universe. In the struggle between light and darkness, he must protect not only the world, but also the people who will one day stand by his side.
It's better to watch this than to read the original work. The protagonist is no different from the indigenous people. The protagonist has no relatives or friends, but his identity is exposed for the sake of the people around him? Killing monsters and conducting experiments on human beings? I got addicted after reading a few chapters