The Status of Xerath
As far as League villains go, I rather enjoy Xerath's narrative and motivation. Power. Its so obvious and simple, yet he applies it in such a new way. It isnt about world domination. It is about ruining everything that Azir built, and making sure all decendents of Azir are crushed and eradicated.
So I believe his visuals and VO stack up rather nicely. I have heard people say that he needs a vgu. I disagree. His visuals are enjoyable and display that raw power that he emanates in lore. I do agree some tweaking needs to be done to enhance Xerath's place in the lore universe.
Voice: I like that Xerath sounds like what a pure energy being would sound like. I believe more menace can be added and more lines that are more personal, referencing the wrongs he believes were committed and his plans (Think Morde in terms of lore exposure through the VO). In addition maybe some tweaks to the voice itself, adding more of an echo, similar to Dark Star skins, but keeping his voice resonating with energy, rather than dark and cosmic like Dark Star Thresh. Also, I would enjoy hearing more rage in his voice because as it stands, the emotion being shown is more of a cold calculating mage type, which is good, but a darker feel would benefit X.
VFX/SFX: So I play Guardian of the Sands Xerath, as I love the gold theme. His other skins could benefit from some texture improvements (I occassionally use his classic skin, but the other older skins aren't as good in my view) to help him feel sharper and more powerful like GotS. Also, the older (including classic) skins could use a vfx update to make his magic look more like swirling raw power, rather than lightning (which does represent power, but makes him look like an electrical mage and not just a raw power mage). Also vfx to create a terrifying raw power sound (i enjoy GOTS sounds) that makes X sound more like a mastery of the arcane.
Those are my main points. I know he could benefit from a full vgu, but he really doesn't NEED one compared to older champs (cough cough, Udyr) and with these changes can fit well into both his and LOL's lore as a whole.