At first, everything had seemed good after the World Tree. Setting the auto-destruct, Pyra and Mythra had made their escape with the others and they had all started their new lives in the new Elysium. At first, it seemed like they had come out pretty well.

Then the cracks started to show. The first issue was how that Pyra and Mythra had stayed in their combined state ever since they left the World Tree. At first, Rex had not paid it much mind, but when he did ask about it, they brushed him off. However, he knew that something was not right.

Other signs started dripping in more slowly. They would start forgetting things. Simple things. On a trip to visit Tora, they could not recall Tora or Poppi's names for over an hour. They laughed it off, but Rex was concerned. Then there was their behavior. They were acting increasingly erratic, and the shaking. More than once Rex had caught them shaking, and at other times almost freezing in place.

It all came to a head one night when Rex was awoken by a sharp ruckus from next door. Throwing the covers off, Rex dashed for the room only to find the girls thrashing about in the covers.

"Shhh," Rex tried grabbing hold of them to calm them down, "I'm here."

They clutched at his night shirt as if their lives depended on it sobbing even as they calmed down, "I-we're…scared, Rex. We can't really tell where one of us ends and the other begins. We're…we're losing ourselves."

Rex responded by stroking their hair, "Don't worry. First thing in the morning we'll go to get you looked at. Don't worry," Rex said the last bit more to himself than to them. He was mortified, but he would put on a brave face for them.

Things went downhill from there. After arriving at the best blade lab in Mor Ardain, their condition started to rapidly deteriorate. So much so that their friends were called in. Rex rarely left their sides as they drifted further into incoherence as their minds kept converging.

During increasingly sparse moments of clarity, they were able to convey what was happening. They had been stuck in this form. It had started gradually at first, but their minds started bleeding over until they had trouble distinguishing who was who. They were slowly losing themselves, and it terrified them. More than that though, it was causing severe problems with their minds. They could no long function with the two of them inside.

The worst part came later. They had told Rex that their time was limited. If any of them were going to live, then one of them had to go. Moreover, they were not really in much of a condition to do it themselves. As a holder of part of their core crystal, it fell to Rex to make the choice. Choose which one lived and which one died, or all three of them died.

Needless to say, Rex did not take this ultimatum very well. It was Morag who suggested that they give Rex some time to think things over and collect his thoughts while Pyra and Mythra descended into another episode barely remembering their own names, or, well, much of anything except for Rex it seemed.

A few rooms over, no one really knew what to say as Rex sat in a chair with his head in his hands. Everyone wanted to cheer him up, but what did you say to someone faced with this kind of choice? It was Morag who once again suggested giving him some space, but he did not realize that she had stayed behind until she spoke.

"These kinds of choices are never easy," Morag spoke in a softer tone than usual, "Take it from a soldier, but if you really care about them, you'll make the choice."

"I-I…I feel terrible about this, Morag…"

"Because you already made your choice."

Rex looked up in surprise. His mouth hung agape as he struggled to reply.

"It's no real surprise who you would pick if forced to choose. I imagine in some depths of your mind, that you made the decision almost as soon as you heard, and you feel guilty about it."

"How could I not? I…I don't want either of them to die. Is it right for me to just pick the one I'm closer to?"

"I know you don't want this, and neither do they. In the end, you have to pick one of them or you all die." Morag prepared to leave, "And if it's any consolation, I'm sure Mythra would tell you to pick Pyra too."

That night, Pyra and Mythra sat crumpled against the hospital bed cradling their knees. It was a horrifying prospect to lose oneself. To not know who was thinking what thoughts. It was a struggle to think coherently, let alone determine who was thinking it.

"This isn't fair," Their voice wavered through the inflections of their shared state and Pyra, "Rex has been through so much already. He shouldn't have to decide this."

"I know," A harsher tone left the same mouth, "I know, but it's how it is. He'll pick…" She froze not even entirely sure who she was, "He'll pick Pyra…I know he will."

"B-but Mythra!" The younger Aegis had a slight grip on herself at that moment, "You're the older one!"

"And you're the one he's in love with," A rueful smile graced their lips, "Just…take care of him, and don't feel bad. Think of it as payment for what I put you through."

"D-don't talk like that."

"Heh, don't worry. You'll be fine. He'll be there for you, and you'll be there for him. See each other through this. You know he'll beat himself up over it."

"I-I…"

"No tears…" Their eyes felt heavy, "No tears…"

The next morning they were barely aware again, but they had made it clear that they did not have much time until the damage would be irreversible. Rex had to make his choice. With shaky hands, he grabbed the Aegis sword. They looked at him in almost confusion even if they never fully forgot him.

"I'm so sorry," Tears escaped his eyes as the sword lit up.

"Ngh," Red eyes slowly fluttered open as the blade regained consciousness. For the first time in weeks, her mind was crystal clear with no invading thoughts, but that alone made her remember what had happened.

'Mythra?' Pyra tried to no avail. It was over. Mythra was gone to save her. It was what Mythra had wanted, but…why did it have to end this way?

Throwing her legs over the side of the bed, Pyra started at seeing Rex curled up in the other bed. He must have been exhausted from staying with them and…that. Her memories were foggy, but she knew he was almost always there. With a melancholy smile, Pyra leaned down and gave him a light peck on the forehead.

This did end up waking him up though. As golden eyes met her fiery ones, Rex suddenly remembered what had happened.

"Pyra! How are you feeling? Is…is Mythra really–"

"Yes," Pyra answered sadly, "But…I think it worked."

"I'm so sorry," Rex immediately launched into his apology, but Pyra cut him off.

"It's not your fault. If anything, I'm sorry you had to go through that. Mythra…I miss her. It feels so…lonely now, but we'll just…have to find a way forward."

Pyra smiled sadly as she intertwined her hand with Rex's, "Yeah. Do you…think we could hold a memorial though?"

"I…I think that would be nice."

A/N: I never said it was going to be a happy story. Just wait till the other two versions come out.