Sarnaga: Congratulations, you have successfully inherited the legacy of the Protoss Empire and become their leader.

Protagonist: Great! Finally I can kill everyone!

Sarnaga: Now, lead them to survive in Warhammer 40k, young man!!

Protagonist: ... Can I still refuse now?

This is a story about a protagonist holding a remnant and a barely native race of Warhammer in this plane trying to survive in 40k.