I personally really like the original better. I don't understand the hate for Kayle's armor or why people think it "needs" to be changed. It's okay for you to not like it and it's okay for you to suggest changes. I don't think it's okay to say that it has "problems" when some of us think it looks just fine.There's no offensive issue that the armor presents unless you really want to reach, so there's no reason for that kind of insult. The design team on riot worked hard on it.
If bright colors aren't your things I can understand why you might not like it. If a sleek armor design isn't your thing, then I can understand why you might not like it. However there's a lot I don't know and that you don't know that goes into the making of a champion. We haven't seen the place Kayle is from, we don't know what her armor is made of, we don't know if armor is even useful for a being like her or just a decoration. These are all things Riot takes into consideration with the lore and art team that you probably didn't even think about.
I don't think Riot's pulling another "hot idolized girl in a body suit with some armor on." I don't think they even pulled that with Kai'Sa. To me it just seems like you're seeing what you want to see. I have no reason to like Kayle's design because of how attractive she is. I'm not into women. I like it because it just looks nice to me. The same goes with Kai'Sa. I'm not saying I can't tell if a women is hot, I'm just saying that's not a reason I would find Kai'Sa's visuals to be pleasing. I will admit that I think Garen is hot... But do I think they pulled another "hot idolized man in a suit of armor?" While Riot has made a few of those kinds of guys, no I don't. There are plenty of dudes that play Garen because they think he just looks like a badass knight that fights for what he believes in. It has nothing to do with his looks.
You also have to consider that there would be no reason for Kayle or Kai'Sa not to have fit, hot and "idolized" bodies. Kai'Sa has been hunting non stop all her life because her void suit will eat her if she doesn't feed it void creatures. Kayle is an angel and I doubt angel bodies can be anything but perfect. Garen is a demacian soldier that has trained a ton, of course he's going to be buff as hell. There's also just nothing wrong with creating hot characters... we like to see them, we like to idolize them. There's a place for darker and uglier designs, and that's not Kayle. They could've possibly took that path with Kai'sa, but how she ended up how she is makes sense in the story. If you want more champions like Illoai and Taliyah, two honestly, still hot females, that stray from the normal hot body type that's okay, but why does it HAVE to be Kayle? Why did it HAVE to be Kai'Sa? It didn't have to. We have plenty of opportunities coming up.
You have to remember that Riot's marketing team doesn't come up with champion designs. Most people see it that way and suggest to themselves that x champion is only this way so it can sell. That's not true. Champions are made by people like us, people who know us and what we find interesting. If you think Kayle is has a nice body... that's because the people behind Kayle also thought the same. The people on the design team are nerds just like us.
Also I'm not even going into the visual clairty, cultural, and very very complicated reason as to why they make a champion the way they look. A lot more than you think goes into creating a champion and you suggesting that it has "problems," and is just another, "hot idolized girl in a body suit with some armor on." Is very insulting to the people who wasted countless, passionate hours on it.
Like THIS "Why is it so open? Almost literally seems so naked and vulnerable. And why is she stripping off more things as she levels up?" Is what you have to say to the people who put that much time into making something for us? And you don't even take into consideration the multiple factors that could answer these questions for yourself? Like I said, why does a being like Kayle who EFFORTLESSLY smites people even need armor in the first place? What matieral do you think is going to be stronger than just her pure magical energy? Do you even know the materials on Runeterra? Can you name one? Runeterra isn't like earth, they have different cultures than us. You're trying to impress your earth-like ideaoligy INTO A FANTASY GAME. Riot's literally created an entire world... and it's not earth. Someone like Kayle doesn't even care if she strips down. First of all, she's covered in light, good luck seeing anything, second of all her intentions are to be a lawful smiter. If you were too meet her and saw her tits, those would literally be the last things you ever saw, so whatever lmao. She doesn't care about your sexual desires, they're literally the least of her worries. What she wears is efficent for her. This is the kind of mindset someone at riot creates a champion with; Attention to detail. It's what gets them hired.