In Honkai, I Am Nexus

[Nexus + frequent appearances by multiple Ultras + high-octane action with no angst + hellish dungeons + native-born protagonist + multiple heroines (or no heroine?) + understandable even if you haven't played Honkai Impact 3rd + some timeline adjustments + power scaling adjustments + some original settings + no transmigration + a few Kamen Rider elements]

Jiang Huai realizes that something is a little strange about this world.

Not only is Honkai everywhere, with no apparent limit, but there are also Dark Lucifer, Zagi, the Yapool, the Chaos Virus, the Absolutian Kingdom, the dark emperor Alien Empera, and a Land of Light where everyone has turned to darkness…

Confronted by enemies filling the sky, Jiang Huai calmly pulls the Z Riser from his pocket.

“Ultraman King, Ultraman Legend, Saga.”

“Ultraman Noa: Ultimate Form.”

Jiang Huai points skyward with one hand, his voice calm as he addresses the boundless darkness.

“Grandpa always said that if an enemy sees me and doesn't run, it's because they've already realized there's no escape.”

“I am the man who walks the path of heaven and governs all things, Tendou Souji. I, Jiang Huai, will shine light upon this world shrouded in darkness.”