User blog comment:Emptylord/Leaked Champion: Vel'Koz/@comment-4290320-20140117171920/@comment-24430045-20140117181553

It's worth noting how different he is from other Void monsters. He really seems to be a mix of the humans and monsters from the Void.

There was two over-arching themes across the three other monsters: insectoid appearance and focus on eating. This guy seems to contain neither of these themes, what with those tentacles and wielding Void energy like the human Void champs.

And all three of your theories are probably right. Due to his vastly different moveset and appearance from other Void champs, I'm thinking he's most likely the "leader" of the Void monsters, perhaps having some hand in creating/controlling them (hence why Kog'Maw might call him "daddy"). I can't think of another reason they'd make him so different from the others.

Tangential statement: I hope this means Cho's VU is coming soon...Year of the Void, indeed!