THE LORE JUST KEEPS HITTING!! SHELBY SHUBBLE GRACE, I CANNOT HANDLE THE THROWBACKS TO SHRUB!
Okay, theory time. The following is a really long winded ramble that's essentially my thought process that got me to the question of 'Where did esmps2!Sausage come from?'
The fact that the hole Shrub built to contain the corruption and her nether portal is found in the Evermoore proves that traces of the original emperors can be found in the empires season 2. Throwback to episode 1 of Pixlriffs' empires season 2 series. He said that titans became the land that civilization arose and fell on. He also stated that none of the emperors emerged victorious to tell history because all of them dissappeared.
Of the 12 original emperors, 4 remained alive and in the present world. (Those 4 being Codfather Jimmy, Guardian Katherine, Wizard Gem, and Fwhip of the Grimlands.) 3 other emperors survived, but left the world. (Those 3 being King Sausage of Mythland, Ocean Queen Lizzie, and Shrub.) This is where Sausage's lore in episode 33 ties in. While he is passing through the multiverse on his way to Hermitcraft, we hear King Sausage's voice telling him that he's "almost at the finish line" and that "all will be revealed soon".
One thing that is very important about this is that the original empires technically survived the cataclysm. By this, I mean that some people had to have survived. So, I think they all came together and moved elsewhere. I think they became the people of Glimmer Grove. Katherine and Sausage are the only people that have actively said they come from other civilizations. Everyone else are just wanderers or whatever. Hence, I asked this. If Katherine is a descendent of the orignal emperors, where did Sausage come from?
Esmps1!Sausage's evil twin was sealed in another reality by Bubbles. There he probably became the tyrant king in esmps2!Sausage's backstory. Sausage talked about how Bubbles was one of his friends back in his old kingdom. However, he never asked how she and Eddie got there.
I think that the council of Bubbles realized they couldn't keep the evil Sausage unsupervised. So, they created a version of Bubbles to go into that world and watch the evil king. But they probably talked about the evil twin escaping the original prison with esmps1!Sausage and they came up with the solution of trapping him in another another reality and using the Staff of Mythland to create a version of Sausage to keep an eye on himself. So when Sausage sacrificed himself in the season 1 finale, he split himself into 3 versions. One as the original Esmps1 Sausage, one as Alsmp!Sausage, and one final version placed in the alternate reality with esmps1!Sausage's evil twin. A version of Bubbles was also placed in that world and somehow gave the power to travel universes and multiverses to esmps2!Sausage when he was born. This leads me to my conclusion:
Empires season 2 Sausage is from the alternate reality that the evil twin was trapped in. When esmps2!Sausage fled from his tyrant king (the evil twin) that was the first time he jumped realities. The reason he stayed in the season 2 universe (the original world, just a few thousand years later) was probably due to Bubbles giving him a power boost and locking access to the alternate reality. She then went with Eddie into hiding until it was safe enough to jump back into the original world.
Sorry this was so long, I had a lot to say. Thanks for reading this very, very, VERY long ramble.