Author Note: I have never written this ship before, but with the way the series ended I am ready to give them a shot.
When Catra was young, and even as she grew older, Adora was her only friend. Sure, she had plenty of acquaintances, but they barely even registered on her radar. Only Adora was there, constantly by her side.
When she yelled insults at someone and got spooked off, Adora was right behind her. When she kicked Lonnie in the shin, Adora came to her defense. Not that she needed the help, but she couldn't deny it was nice.
In training, when they were surrounded by bots with nowhere to turn, Adora was there at her back, ready to defend.
After being scolded by Shadow Weaver yet again, for doing absolutely nothing wrong, Adora provided a gentle touch and reassuring word.
When Adora hugged her, her heart soared. Catra was often unhappy, but a few words from Adora could turn that around in an instant. She was like a bright light, drawing Catra to her.
She had always been there, and when Catra thought about her future Adora remained a constant. In the next few years she would help Catra strike down Shadow Weaver and lift Catra up to take her place. Maybe they would teach the next generation of Horde soldiers, or go out and wipe out the remaining princesses together. They could even start a brand new squad, if Hordak approved. They would rule over the Horde, side by side as they always had been.
Maybe not just as friends, but as partners. As Catra grew older, the idea gained traction in her mind. At first it seemed gross, but it grew on her. She didn't know much about relationships, but wondered what it might be like. To hold someone's hand, without recoiling away, to be even closer to them. To always be together with one special person. The thought warmed her from the inside.
She wondered if she might reach out to Adora and give it a try. What their future might look like if she did. It was a pleasant thought, far more so than most of her ideas. It was spurred on by her rapidly beating heart, her way too easily lost composure, the gentle tilt of Adora's smile.
There was no hurry though, Adora wasn't going anywhere.
At least, that's what she assumed.
That was, until reality kicked in.
In the span of only a few days, Adora was gone. She had abandoned Catra just like that, without a second glance, without a chance to make her stay.
Catra couldn't make her stay.
She wasn't Catra's friend anymore, no. She had made all new friends, found an all new home. An all new place to be that wasn't with Catra.
She invited Catra to come, but that wasn't their place. They belonged in the Horde. Adora belonged with her. They were going to work together, to live together. Catra had imagined how it could be, how she wanted it to be.
Everything they had together, Adora had just thrown it all away.
She threw Catra away.
Clearly Adora hadn't felt the same way, hadn't valued their friendship or any other potential that Catra just wanted to forget.
Getting promoted to Force Captain made it easier to forget.
Her newfound success came as a surprise, though not an unpleasant one. She had never expected Hordak to promote her to Adora's old position.
That brand-new winning streak only continued. Catra was able to get the upper hand on Shadow Weaver, was able to run operations, and was able to impress Hordak. All of this only occurred because Adora had left. It was a funny coincidence, but somehow it felt like fate.
Fine then, if that's how it was going to be. Catra dropped her old ideas of the future away. Time for a new plan, one without Adora.
The plan was this, rise through the Horde leadership all on her own. Replace Shadow Weaver by herself. Rule squadrons and go on missions alone.
Catra didn't need Adora. She would make her own future, plan her own course. If Adora could throw Catra away for new friends, then Catra could do the same.
It was one thing to say that she didn't need her, it was harder to pretend that she didn't want her.
Survival in space was quite different than survival on Etheria.
Catra had long given up on any kind of future. She was fighting to make it just to each next day.
She sent Glimmer into space as one last apology, with her last words to Adora. Catra would never see her again. She would probably die on this ship, in captivity. There was so much she never said, so much she kept locked away. It would go with her to the grave.
But no, Adora couldn't just let her go. That fool always went charging in where she didn't belong, even to save someone who made as many mistakes as Catra had.
When Catra regained consciousness to see Adora's face above her own, it appeared as if an angel was holding her. She wondered if she had died, but no she could still feel the pain in her body.
It took all she had to say, "Hey Adora," and then return Adora's hug with all her strength.
She got some rest and hid away for a while, not sulking she was definitely not sulking. Of course Adora wouldn't let her hide forever, and even stayed with her as she started to get Hordak Prime's chip removed. It was a relief, far more than Catra expected, to have Adora there. Her presence was soothing.
Once the chip was off, she supposed she should join the rest of the crew.
It felt strange, the next few days. It was full of new experiences, like dealing civilly with Adora's annoying friends. It was also full of things that rung familiar in Catra's memory.
When fighting side by side once again, Catra was quickly able to fall back in step with Adora. Their combat styles had changed a bit since they last fought together, but their years of teamwork meant that they could quickly get back into the groove. It was easy to reconnect.
Something that wasn't as easy was when Adora laughed, tears in the corner of her eyes from joy, Catra's heart, which had tried to forget, jumped to a faster rhythm. She could only stare at the girl who shined like the sun. She remembered how she used to feel, how she had tried to forget.
She didn't want to forget anymore.
Catra would tease Adora, tickling her in all the same spots as before with exactly the same effect. Adora would tease back, giving just as good as she got it. It felt good, it felt safe. They were finally moving in the same direction once again.
When they got back to Etheria, much of that continued. They fell back into patterns, into routines. Into continuing their relationship from an all new starting point.
It brought back long buried thoughts.
She wondered what they would do after the war, if they won of course. There was a chance that they would not win, that Hordak Prime would demolish their planet. No future to worry about in that case.
But if they did win, Catra wondered how it would be. Would she stay with Adora, would Adora even want her to stay?
She wanted to, more than anything. This was different than how she had felt before, when she was living in the Horde. Previously it was all tied to their success, to their position in the Horde and material accomplishments. These feelings were new, no, they had evolved.
Catra wanted to be with Adora, day in and day out. She wanted to be there for her, to be together. Catra would jump into fire if it meant saving Adora, she would do anything to protect her. She wanted to be by her side, to be her partner. It didn't matter where they lived or what positions they held, as long as they were together Catra would be happy.
Adora didn't feel the same way though, that much was clear. That foolhardy girl was always trying to sacrifice herself to save the world, always leaving Catra behind. Always trying to selflessly play the hero, while sacrificing her life and future in the process.
At first, Catra was resigned to it. She left, not wanting to watch Adora go on some cursed suicide mission. Again, she would have to find a new future.
That changed when she saw what Hordak Prime was doing the planet.
She should never had run away. It was a huge mistake to think that she could leave Adora behind. That had never worked in the past, and it wouldn't work now.
She had to help Adora.
Even if Adora didn't feel the same way, even if she turned Catra away and didn't see their future the same way, it didn't matter. If she needed Catra's help, then Catra had to be there.
She had to get to Adora, no matter the cost.