Even though Hortus seemed like any normal Synthetic World, Synthetic World and normal themselves were oxymorons.
It seemed to exist in the Inner Space like its peers, but in reality, it's a separate space-time in itself and showed the characteristics of being a separate cosmos.
Like every other Synthetic World, it's extremely useful to carry armies across interstellar distances. But its usefulness far surpasses that by allowing the lord of the world to 'bestow' powers upon others and even forcefully strip them off.
Synthetic Worlds themselves were exceedingly rare and usually only found in Kingdoms or Empires.
They're the living testimony of an ancient power that reached the peak of all divine paths.
Opening up a separate space-time field? Possible. Creating new life and death cycles? Sure. Constructing a new order and chaos in a domain? Yes.