National Fate: I’m Here to Transform and Play Laigushi?!

The protagonist comes to his senses and discovers that he has been bound to a System and transformed into Laigushi. Just as he figures out the world's background, he gets pulled into a national-survival game. The first instance is Earth from Warframe, and his teammates are Welt Joachim Yang from after the end of Amphoreus in Honkai: Star Rail; Fu Hua, during her school days alongside Kiana in Honkai Impact 3rd; Void Archives, who has just crossed through a Star Gate and looks a lot like Otto; Su Wanning, a sweet, clear-eyed and incredibly lucky college student from the Dragon Kingdom on Blue Star; and Lu Feng, an elite special-forces soldier who made it through a series of rigorous selection trials.

Volume One: Laigushi, Welt Yang, Fu Hua, Void Archives, Su Wanning, Lu Feng

Volume Two: Laigushi, Nod-Krai's Ying + Paimon, Sushang and Guinaifen from Honkai: Star Rail, Big Herta, David Martinez and Female V from Cyberpunk, and Lucy

Volume Three: Laigushi, Kevin Kaslana from Senba Academy in the Previous Era, Elysia from the same period, Welt Yang from the Second Honkai Eruption in the Current Era, Anby Demara from Zenless Zone Zero, Belle + Eous, and the Super MOD King Steve from Minecraft

(Updates whenever I feel like it... ongoing)