u/Top_Fig_114

In short, it can be summarized as: what would their reaction be to the Traveler's Light? I completely expect the Empire's reaction to be heresy, but the Star Wars story might be something more interesting.

Bonus to consider warhammer fantasy because i kinda like it more than 40k

Bonus round if considering the stuff from aos

This Is battle against a Jedi with a force sword wich Is not a ligthsaber against a chaos individed chosen from warhammer fantasy with a demon sword

Round 2 a chaos sorccerer

It might sound a bit far-fetched, but I find the comparison between the Chaos Warriors of Warhammer Fantasy (pre-End Times) and the Sith better than the Space Marines, at least in ancient times before lightsabers, although that could be another debate regarding daemonic weapons versus a lightsaber.