system
Given the following post, respond as if you're commenting on Reddit:
human
[Chronicles of Riddick] So, what is the underverse? And what's the Necromonger's end goal?

If i understood the movie's lore correctly the leader of the Necromonger saw/found something on the underverse which is why they are going around turning other species into Necromongers (like they did to the Furyans) their main goal seems to be related to the Underverse, either to go there themselves or to make it "appear" in the normal galaxy, i didn't understand it completely. 

But what is it? Is it some sort of afterlife? Another dimension? Another universe?
gpt
In this verse, life is antagonistic to the natural state. Here humans in all their various races are a spontaneous outbreak. An unguided mistake. The solution lies in another verse. A verse where life is welcomed and cherished. A ravishing ever-new place called the  Underverse... but the road to that verse crosses over the threshold.

When you look up to see a group of shooting stars it is already too late. What you are seeing is an army, an army unlike any other... crusading across the stars toward the UnderVerse, their promised land - a constellation of dark new worlds. Necromongers, they're called. And if they cannot convert you, they will kill you. Leading them, the Lord Marshal. He alone has made a pilgrimage to the gates of the UnderVerse... and returned a different being. Stronger. Stranger. Half alive and half... something else.