There needs to be a meaningful delineation between what an Aspect and an Ascended are.
An Aspect is supposed to be an avatar of a greater celestial power, to do their will on Runeterra
An Ascended uses the celestial power of the Sun via the Sun Disc to imbue the themselves with power
They draw power from the same well but they are NOT the same thing. The meaningful difference, yet shared nature of their power is what drew me to the lore please don't homogenize them.
What's so cool about the Ascended and the Aspect and the relationship between Targon and Shurima is that it's suggested that Targon gave Shurima the Sun Disc to create warriors capable of facing the Void during the great Void War. Shurima formed a culture around the Sun Disc worshipping the sun and eventually used it's power to form a full-blown empire. They became prideful calling themselves god-warriors even Azir was a victim of this pride which led to their fall. When the Empire fell, the Ascended showed the true nature in their hearts and became Darkin, giving into to their base desires for power. And when it gets out of hand and someone has to clean up this mess it's Targon that had to fix it, devising the method for containing the Darkin in their weapons.
This is a beautifully crafted relationship between the two nations. Shurima thought they were godly warped their whole culture around the power of the sun, but that power was never theirs to begin with. They were just puppets of the Targonians the whole times. It humanizes the Ascended and shows that even these "gods" are capable of folly.
I was excited about the Iceborn as well. Being that are cut from the same cloth but emissaries of The Void. I really wanted to see the procedure they went to to become Iceborn. The meaningful difference being that Iceborn is hereditary. A Sunborn probably can't reproduce and have kids with powers but the Iceborn can because they maintain human form. Now I'm a little skeptical if this is true.
Look I made a thread when Kayle and Morgana were announced showing how they could still be human when Aatrox calls them Ascended because they need to look similar to their original design.
The tl;dr is to make Kayle and Morgana sister mages forced to flee from Demacia after their powers are discovered, they flee to Shurima together and Kayle ATTEMPTS to become Ascended while Morgana tries to dissuade her from it. This way Aatroxs' quotes still make sense and the adversial nture of Kayle vs Morgana is expanded upon by looking closer at their family relationship.
You can read the full thing here
https://boards.na.leagueoflegends.com/en/c/story-art/5Ze9bjn1-theory-on-kayle-and-morganas-relationship-and-origin
Please do not change established rules of the universe just to make Kayle and Morgana work I beg you, Riot.