Lord Special Emissary

It made sense for the Emperor to want Khan. The former was an existence driven and fueled by war, and Khan had offered him the greatest of them all.

The Emperor had probably already made up his mind back in the Royal Palace. He only had to confirm whether Khan wielded the power to bring that war home, and the battle against Lord Mighty had cleared any doubt. Lordships, domains, and everything else were secondary as long as the Emperor could get his hands on the conflict against the scarlet eyes.

Ethical problems littered that offer, but both Khan and the Emperor were beyond mundane beliefs. The former had done his fair share of shady things, and his newly summoned darkness made him ready for much more.

As for the Emperor, his whole species was built on endless expansion, growth through battles, and pride from strength. Khan didn't know which came first, but the Emperor was basically doing the Empire a favor by adding another war to its to-do list.