@Riot, whats your stance on customs skins?

Like lets say I grabbed Final Boss Veigars Orginal Files, changed the animation colors, the colors of the model etc.

Would I be able to use the custom skin? I've heard Riot allows for them, but idk if using base models an animations for newer skins and changing them is allowed?

I know the TOS says "Blah blah blah, dont edit in game files", but Riots allowed customs skins before even out right said they encourage it, but I'm not specifically sure about the example i stated above.