Shao Kahn has been merging realms for thousands of years, and Onaga for thousands of years before that.

Just how many realms have been absorbed into Outworld? Arnyek, Osh-Tek, Collector's realm, Vaeternus, Kuatan, Zaterra, Edenia. Tarkata maybe?

Then there's indipendant Orderrealm (Seido), Chaosrealm, and the Dream Realm. Including Earthrealm, and Outworld's base realm that's 13. *Edit: 14, forgot about Netherrealm. Do the Heavens count as a realm?

Ka-Tra

Unprecedented realms integrated with the main realms, Outworld swallowing the most. Would like to see them all set free, but it may get legislative.

I would like to see them free as well. Kind of like a middle finger to Shao Kahn making his life's work meaningless. But there is a lot to consider. Like do the people WANT their realms back since they are so used to Outworld? Interesting scenarios.

Well Onaga wasn't about merging realms into Outworld. He was more unifying Outworld and ruling it all. Merging them was Kahn's idea after he killed him. Kahn's been merging realms for thousands of years so who can say really but I like to think there are a LOT more realms out there we just don't know about.

Is Outworld the only Realm merging other Realms into it?

Ka-Tra

Yes, Shao Kahn is the only one in all the realms that has this desire. You could make an argument that he's subtly being manipulated by the One Being.

Mortal Kombat has flushed itself down the "multiverse" toilet thanks to all this time-traveling-hour-glass bull shit.

So the answer is an infinite amount of realms. Sad, really.

Some scientists believe that about our actual reality. I'm more worried about the timescale. If other Kahns ruled Outworld, when was it?

Onaga is supposedly the 1st Outworld Kahn, and Shao immediately took his place. When/where exactly do these supposed other Kahns fit in?

Ka-Tra

That part of MK history is very vague. Kahn's rise to power definitely precedes his Conquest of Edenia. Maybe Edenia was his first realm conquered, maybe it wasn't and he conquered few realms before that. Maybe Kahn poisoned Onaga hundreds or thousands of years before Edenia.