How powerfull do you guys think Morgana and Kayle will be in-lore after their VGU?

Pre-darkin Aatrox level. He was basically shuriman male Kayle anyway. Winged and benevolent entity with shinning gold armor, enemy of darkness, protector of his realm etc. And Aatrox was an extremely powerful Ascended capable of defeating spirit demigods like Ornn, Volibear.

Will be surprised if they end more powerful than Xerath though. Especially since even Nasus and Renekton couldn't defeat him together when he was at his weakest. Current Xerath is a lot more controlled and disicplined while also sarcophagus is getting weaker.

Aspect-level. Stronger than most Ascended and Darkin, but not as strong as Ryze, Lissandra, Vel'Koz or Demigods.

I suspect they will be strong enough to defeat a Noxian war band/ army on their own, but not strong enough to bring down large void constructs without difficulty.

Hard to say but maybe around the levels of most other Ascended. Possibly more powerful than them as a whole, maybe even up to par with Aatrox considering they could have stuck around the world for much longer but maybe not as powerful as say the Aspects, Ryze and anyone of that level+.

I think that they will be depowered. People assume that Kayle will be Ascended because of the context-less Aatrox quotes but his designer actually stated on Reddit that he doesn't want to make them Ascended.

Kayle rn is a ranged melee hybrid that scales into becoming a ranged powerhouse. To me this opens up the oppurtunity to make Kayle a Ascendant-prospect somehow who is chasing Ascension and becomes Ascended over the course of the game like Kayn becoming the Shadow Assassin or Rhaast.

So I think they are just ordinary mages