They are fake sovereigns who became sovereigns by fusing with the seed of power of dead Sovereigns. This will ensure that they are weak and cannot become Origin gods without attending the trial of heaven.
The Tower of Supremacy is full of luxury slaves like them. They serve the Supreme Beasts with all their lives including their bodies. As long as Supreme beasts can pay for them, they can even kill one and eat it.
He is certain of this rule because he confirmed it. He tried once but he decided it was too expensive to indulge in it no matter how delicious the flesh of a Sovereign is.
The Sovereign slave led him to the teleportation circle while others activated it. It is more of translocation since the space where he is in will be locked and swapped with the space at the target location.
