They have done every - freaking - thing under the sun! While I would say that some of their stages are stronger than others, they still excel at whatever they are doing, and I'm really excited to see them in the future!
So first off, one major theme in Oneus is the moon! It features in a lot of their music videos (except ASWE), and is mentioned quite a bit! The moon is also part of our fandom name, "to moons", since we orbit around oneus like the moon orbits the earth!
First off, this iconic Lit stage from RTK! Lit was a traditional Korean song, but I think this stage from Road to Kingdom really emphasized how amazing this was! The dancing, the props, everything was spot on, not to mention Hwanwoong really shined here! Lit was all fun, almost bright, which is a shift from Oneus's normally darker title tracks. But this still contained the elegance that infuses every single one of their songs! Fun fact: the person rapping in the chair during their RTK stage is actually one of their main vocalists, who was injured at the time. Seoho can rap, sing, and tumble with the prettiest smile on this earth! 
Music video:
A song Written Easily! The soft boys and this soft song, with all of those flowers! The whole music video is really just so pretty, and one of the best in terms of aesthetic that I've ever seen! 
The concept is wistful, and sad, but still so neat and beautiful, and I just really like it!
We also have our tough boys! They recently came out with No Diggity, which isn't my favorite track, but shows a very unique side of them. While the dancing was perhaps simpler compared to other 4th gen groups, but it was had a very Oneus flavor to it (oneus typically include ballet of some form in their choreo, and in general tend to have very elegant choreo with a Very recognizable style. If you watch enough of their dances, you'll see it) And some of them really showed their psychotic sides in the music video!
Plus some of their makeup looks in the stages
As a sharp contrast to my previous point, they also have a cute side! Oneus has a lot of bsides that they perform, most notably them performing Airplane during Lived promotions A LOT! Some of the cuter songs include the already mentioned airplane, English Girl, Zigzag, Bing Bing. They are all a little bit older, but perform with smiles and energy that are unparalleled!
And finally, oneus has something that they excel the most at, that they do frequently, and that is their supernatural side! You heard me, Oneus are actually vampires who got cursed by Helios and they have a whole backstory with a child, but more importantly it involves guns, swords, and awesome tables! I'm gonna split this up into 3 parts, so here we go!
Their debut Valkyrie started out with featuring some of the supernatural bits, and while it's not obvious, there are some seemingly magical things. First off, the very name of the song, Valkyrie is a creature from norse myths. I'm not gonna get into them too much, but they were basically winged women who took honorable soldiers to their final resting place in Valhalla. But there are some interesting parts of the MV, such as the moon behind Ravn, the sorta icicles behind Xion, and that magic flippy thing with Keonhee and Seoho.
Now, getting even stronger. Twilight isn't explicitly magic either, but it's aesthetics are definitely vampire. Oneus in an Italian mansion? Sun centered aesthetic? A specific emphasis on reflections? But the ending really sets it up, with Leedo staring at a wolf, which the camera then angles to his eyes, which contain the wolf's reflection.
And finally, the real storyline. Oneus created multiple story/concept films for Lived, which established them as vampires. While it may not be explicitly stated that they are vampires, I think that people who live in eternal night and drink blood from humans def qualify. They outdid themselves, creating a rich and intriguing world, with dark elements that are interesting in the bubbly kpop world. I mean, bathing in blood? Fighting monsters? Protecting magic children? Sounds interesting to me!
Mvs:
Well, that's it for now! I just wanted to create a thread for oneus, and I think that they really prove themselves on stage! there are plenty of things and concepts I didn't include, but that's for later. 
