(Ooooh, the first half of this one is very angsty :3)

What if, Rainbow Steve was still able to be saved when Void took the Crystals... but not in the normal way you'd think?

In this AU, Sabre ran toward Rainbow and tried to stop him from splitting himself apart when that happened. Time was able to freeze both their time states, but it was a little too late. Rainbow had been shattered, and Sabre was missing his left arm, some of the left part of his face, half his left leg, and a little bit off his fingers on his right hand, all seemingly to have just melted away without actually causing injury (the spots where the limbs/parts used to be look like melted flesh-colored wax).

Time was able to bring them both back to the Hub, and got Sabre some temporary prosthetics for his arm and leg, while he got his face and hand bandaged up. What happened with Sabre and Rainbow was while Rainbow was mostly fine physically, his mental state was broken, and that was swapped for Sabre. Therefore, Sabre was still able to think clearly through all of this. Eventually, the whole 'Traitor Rainbow" thing happens, and Sabre is left missing half his limbs and face, his best friend corrupted and lost to Darkness.

Skip forward to when Void has Rainbow locked in a machine in the temple, Sabre and Elemental being restrained. Void is just about to flip the lever, but then Sabre somehow breaks out of the restraint and tries to save Rainbow by breaking the glass and pulling him out of the machine, while he's still connected unknowingly to Sabre. Unfortunately, just like before... it's too late. Void flips the switch just as Sabre has a hold on Rainbow, and they both scream out as they feel an indescribable, painful energy coursing through them. Lightning strikes around the two and Void, the machine doing its job.

However... something's different once the lightning ends.

As Void absorbs the energy of the Crystals, becoming Rainbow Void, he looks over to where the machine is when he hears something fall to the ground. There, lying on the floor, is a single figure covered in prismatic color. Void thinks nothing of it and turns to Elemental, who is panicking and crying over the loss of his two friends. Void saw what Sabre was doing when he activated the machine, and thought that he just ended himself along with Rainbow, so all he really had to do now was kill the second intruder.

What he doesn't know is, two souls are waking up nearby.

Sabre opens his eyes, not feeling the blindfold over them, as he realizes he can feel all of his limbs and other eye.

Rainbow opens his eyes, something pulling his mind back together, and realizes he isn't corrupted anymore.

Lightning suddenly surrounds the figure on the ground next to the machine, and Void looks over at the mysterious, powerful lightshow, Elemental doing the same. A lightning bolt shoots out at Void, knocking him across the temple, and he hits the wall opposite from the machine. Void angrily looks to see who had done this, as the lightning calms down, but when he freezes when he sees the person standing there... or rather, people.

In front of the machine is what looks to be a combination of Rainbow Steve and Sabre, prismatic pieces of color covering Sabre's dark green shirt and blue jeans, however sharing skin colors and hair colors in the form of splotching in random places. A symbol of a crystal adorns the left side of the figure's face. The figure's eyes are both extremely different; The left eye having a white sclera and orange iris, while a darker orange diamond-shaped pupil sits in the middle of the iris. The other eyes has a black sclera, and instead of an iris and pupil, there is a moving line mimicking one on a heart monitor that's constantly changing colors, cycling throughout the colors of the rainbow.

This figure is both Sabre and Rainbow, merged together in an amalgamation of a form between two species that were never meant to clash... yet they do not separate. This... is the Prism Amalgam.

Sabre and Rainbow fight off Void, and try to make sense of what's going on, while Elemental has a mix of a heart attack and mental breakdown. Eventually, they all calm down enough to go back to the Hub, seeing if someone there can fix this.

Spoiler alert: Nope, nobody can fix it. However, all of them soon realize they wouldn't want to have it any other way.

Rainbow and Sabre happily stay fused, fighting the Darkness off and taking back the world form the Darkness. Once all is said and done and the Rainbow Kingdom is built, the Rainbow Crystal dropped from Void safe in the Citadel, Sabre and Rainbow continue to stay fused, as they were glad to never be separated again.

And of course, harmless chaos ensues inside the house between them when nobody's visiting :)