First off, while I approve of unifying the splash arts across all regions I also believe that NA has some of the better splash arts. Some are more contested than others (for example, I like the NA Masquerade Evelynn better than the proposed one).
That being said, let's focus on Crimson Akali.
Here is what you want to use:
Here is what we currently have in NA:
Let's talk about what we currently have is superior to what you want to replace it with.
* In the NA version, her eyes are well defined and expressive. In the replacement... there is something off about their shape; particularly her eye lids; It looks like someone punched her in the right eye.
* The NA version closely mirrors her in game model; the replacement does not (Missing armbands, the border to her clothing is black in game, not gold).
* The NA version displays that she dual-wields. The replacement does not.
* The NA version has a certain tranquility to the background, highlighting the action of the motion Akali. The replacement has a scene from possibly hell in the background.
* The NA version is rated PG; the new version shows a bleeding, decapitated head (R rating).
* The new version makes Akali look out to be some blood crazed sociopath holding her bleeding trophy. That is not who or what Akali is in her lore or what her new lore is looking to become based on the brief mention in Shen's updated lore.
* There is something wrong with Alkali's left leg in the replacement version; it's like her left shin/calf is half the width of her right. Before you talk about perspective, realize that her legs are crossing at the shins. Similar, her right thigh is disproportionately larger than her left, and since her right hip is actually further from the camera, this is doubly wrong.
* The level of detail in the NA splash for Akali herself (which is the focus of the splash) is superior than the replacement.
Seriously, the only thing I noticed that the new splash art has over the current NA version is Akali actually has nipples, which is an oddity for females in league of legends as I believe something Riot has traditionally kept out of splash arts. I also don't see any value in adding something like that, so I'm not necessarily sure this is an improvement.
Thanks for reading.