Which side ultimately "good" or "just"?

The fascist imperium or the free chaotic legions

The Imperium, obviously.

For the horde!

Shit, wrong universe.

Chaos is beyond morality.

The Imperium is brutal but is at least fighting for the collective good of Humanity. You get some venal and corrupt governors and generals but the Imperium's shot-callers are true believers in the cause.

How so, when the slightest waver in belief in an unseen God emperor warrants death?

>Chaos
>good
>just
>ever

Are you retarded?

The imperium are still the good guys. It would be a disservice to humanity to allow rebellion and corruption to end the imperium and swallow man kind whole.

Compared to Chaos who won't let you live regardless if you're a hapless victim of some random raid? Whatever faults the Imperium may have, at the very least it's doing its best for the sake of mankind. Chaos is straight up evil from the get go. It's the literal embodiment of evil.

Everyone's an asshole in 40k.

Op here. While the actual forces of chaos can be perceived as evil, their gods ( or at least two of them) are not truly evil.