I need to change the terms for things. Please help with brainstorming.

[radraccoon]

The world my story takes place in is divided in two parts: one that gets a lot of sun and one that doesn't (there's a whole thing about how this occurs, none of which is explained in the book as it ties to that world's creation myth, which isn't explained until well into the second book). I've referred to them as the World of Light and the Land of Darkness, respectively (World and Land specifically used to show how little people think of the darker half, even though they're the same size, again never explained but the word use implies it). However I was recently told those names are stupid and make it sound like it was written by and idiot (well, they used the r-word). One person even said they stopped reading the first time I used these terms.
So what are better options? Do I use more fanciful names like "Sunlandia" and "Moonsville"? Completely made up elven words with improbable strings of vowels, consonants, and apostrophes? Maybe more poetic terms such as The Sun Kissed Lands vs. The Moon's Home?
Also they didn't like that a race of powerful beings call themselves Dread Lords (if they rule a domain, the race are called Wraiths). Said nobody would call themselves that. Again, I'm trying to imply a cultural aspect to the Wraiths. "Dread Lord" is consistent with them naming a farm "Withering Fields" or a woods the "Hangman's Forest" (which they decorate trees with nooses). They're trying to be oppressive and scary, but because they're immortal and powerful they're out of touch and don't realize it's a little silly. My only problem with the name Dread Lord is that "Lord" is gendered, and these beings don't have genders. Is there a better neutral alternative?

 

[Prince_Azmiran_Myrian]

I've referred to them as the World of Light and the Land of Darkness, respectively (World and Land specifically used to show how little people think of the darker half, even though they're the same size, again never explained but the word use implies it). However I was recently told those names are stupid and make it sound like it was written by and idiot (well, they used the r-word). One person even said they stopped reading the first time I used these terms.
So what are better options? Do I use more fanciful names like "Sunlandia" and "Moonsville"? Completely made up elven words with improbable strings of vowels, consonants, and apostrophes? Maybe more poetic terms such as The Sun Kissed Lands vs. The Moon's Home?

Maybe something like, sun/moon's domain (or demesne?) And Twilight/Dawn's Domain?

Also they didn't like that a race of powerful beings call themselves Dread Lords (if they rule a domain, the race are called Wraiths). Said nobody would call themselves that.

My only problem with the name Dread Lord is that "Lord" is gendered, and these beings don't have genders. Is there a better neutral alternative?

Something with Master, Ruler, Sovereign, Liege?
Or maybe since they are known as wraiths... Reaper, Spirit, Lich, Revenant, Nightshade. Unless those things already exist in your world, then they may not be appropriate.

 

[Cipiteca396]

However I was recently told those names are stupid and make it sound like it was written by and idiot (well, they used the r-word). One person even said they stopped reading the first time I used these terms.

Good riddance. Next time someone like that shows up, tell em to fuck off. The names are fine. Maybe they can be improved, but they're not wrong.

World and Land specifically used to show how little people think of the darker half,

You could try province, wilds, fringe, frontier, rim or country. Those words can have a derogatory tone to them when used by more civilized folk. Similar words work just as well, as long as you put in the effort to make it sound like an insult. Synonym for 'In the middle of Nowhere'. Territory, Expanse, Border, Realm, Reach, March, or End can also work.

Almost forgot, for the light and friendly place: Shelter, Grand(), Great(), Heroic(), Radiant(), Fair().

For both, it might make the most sense to give it a made up name like real life places. But whatever.

My only problem with the name Dread Lord is that "Lord" is gendered, and these beings don't have genders. Is there a better neutral alternative?

Monarch can also work. Despot or Tyrant, if you want them to double down on being intentionally evil.

 

[K5Rakitan]

My only problem with the name Dread Lord is that "Lord" is gendered, and these beings don't have genders. Is there a better neutral alternative?

I'd make up a word for this.

Lord
+
Lady
=
Laordy

You can use that or play with more words until you get something that has the right ring to it.