so riot has a new skin for velkoz they can release but don't.
No, they don't have a new skin for Vel'Koz. You're just assuming they do because they have an asset that conveniently looks like Vel'Koz. (for gameplay purposes)
Rioters Bioluminescence and RiotVitzkrieg both discussed it in this post that they aren't Champion Skins, but rather entities in-and-of-themselves designed specifically to serve as enemies in the PVE Gamemode, Invasion.
To directly quote RiotVitzkrieg, I'm going to basically plop his comment down in a quoteblock.
Heyo, sorry for the confusion! Let me help clarify where we're at with those custom SG monsters.
As I mentioned before, we didn't build these to be champion skins. What that means is that aside from some tech limitations (they're actually new characters instead of skins, and use some new tech that hasn't been back ported to the original champions), we didn't even consider how they'd fit the champs as playable characters. That means we didn't do our due diligence we'd normally do for any new skin (concepting any abilities other than the ones you saw, checking skin readability on SR, cleaning up VFX clarity/performance, etc etc).
All that means is we can't just sell you guys what we have in existence right now. There's been a very loud and clear request to be able to play as these badass monsters, and we hear you! I want to make it clear that I'm not promising anything, but I've started conversations with our skins team about what it'd take to turn these into real skins. We'll see where it goes from here :)
So, to reiterate: The Star Guardian aliens, while looking basically like re-skinned Voidborn, are not actually Skins. They were not designed as Skins, but - due to demand - RiotVitzkrieg is doing some talking with the Skins teams to see if they can be made into Skins somewhere down the road.
