Steven Universe AU because I don't need a reason. Also I think I did good on choosing the fusion gem!
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Our story opens with the sound someone singing. A half-human, half-gem hybrid named Thomas wakes up in a cell and sits up. He mumble the names of two of his guardians, hoping they'd respond. The child rubs his head before remembering what happened to his third caretaker as a brief image of two gems falling to the ground appears in his memory.

He gasps. "Bloodstone! Where is everyone?" Thomas mumbles as he gets up and approaches the barrier keeping him in the cell. Angry screaming could be heard in the background. In a moment of curiosity, Thomas touches the barrier, then pushes a hand through. He gags slightly, but chuckles, looking at the currents running up his arm. "Cool!" After a few seconds, Thomas pushes himself through the barrier and escapes the prison cell with a shiver. "I'm out. Woohoo! Okay, where is everybody?"

He runs off, mumbling to himself. After a few paces, he stops, noticing an onyx with his gem in his navel sitting a cell, groaning. "Uh... hello? Are... you okay?" Thomas asks. The onyx takes one look at Thomas and hits the wall with his hand, causing Thomas to lose his footing. "Great! This is just perfect!" The onyx yells. "Uh, do you need any help?" Thomas timidly asks, a little frightened by the gem. "No! I mean— Don't look at me! Just... go away." The onyx turns away and curls up into a ball. Thomas begins to walk away until the onyx stops them. "Hey, wait! You're out! How did you get past the field?" He asks.

Thomas turns back towards the onyx. "Oh, I just kind of—" He reach towards barrier. "Wait! No-no-no-no-no, wait!" But before the trapped gem could stop him, Thomas' hand passes through the barrier. "It's... okay?" The onyx reaches towards barrier and his hand gets zapped. He retracts his hand with a yelp and looks at it painfully. "What's going on?" He grumbles with a suspicious tone. Suddenly, the sound of a new male voice singing is heard.

The onyx looks around and gasps. "Somebody's singing..." Thomas whispers, pointing out the obvious. The onyx whispers a name to himself before turning back towards Thomas. "Let me out of here! Please! I need to find him!" He pleads. "Oh, is that your friend? I'm looking for my friends, too." Thomas says with a smile. "He's all alone, I need to find him!" The onyx says, beginning to panic. "Don't worry, we'll find our friends." With that, Thomas steps into the barrier, putting his arms to the side, creating a hole in the barrier. The onyx rushes forward then slides under Thomas' arm before running off. "Wait for me!" Thomas calls after him.

After a while of running, Thomas attempts to start a conversation with his new companion. "Hey, my name's Thomas, by the way, what's yours?" He asks. "Quiet!" The onyx snaps. He goes silent as he focuses, but groans after a moment. "Ugh! I can't see!" He looks around before taking off running again down a winding corridor, Thomas following after. "How many more Gems are trapped here?" Thomas whispers to himself. The onyx, who had heard him and thought he was asking him, answers with, "Don't know. Don't care."

Suddenly the singing stops, causing the onyx to stop running and Thomas to almost run into him. "He stopped singing... Roman!" Thomas glances out a window, seeing the Earth. His eyes widen in shock at how far from home he really is. The onyx start running again, the young hybrid in tow. They find a cell with a Gem in it. The onyx gasps, then deflates when he realizes the trapped Gem is not the one he's looking for. "It's just you..." He spits, venom in his voice.

"Talyn!" Thomas exclaims when he realizes who is in the cell. The trapped Gem turns around, revealing them to be Talyn, the rainbow tourmaline. The onyx starts pacing fervently in the background. "Talyn, I can get you out." The rainbow tourmaline moves back "Stop!" They exclaim. "It's okay. I can--" Thomas is cut off. "No! I don't want your help. Things are bad enough as it is. I've already made too much trouble. Once we get back to Homeworld, they're going to decide what to do with us."

The onyx lets out a loud sigh of frustration. "I don't have time for this!" He yells before dashing off, down the hallway. "Wait!" Thomas yells after the onyx. "Thomas, whatever you're doing, just stop. If we do everything they say, they might go easy on us." Talyn says. "But they're... mean! They hurt my friends, they hurt my face! They've got you here in prison!" Thomas exclaims as he gently strokes his black eye. "That's why we can't fight them." Talyn grumbles. "That's why we have to fight them." Thomas says as he shakes his head. Talyn turns away. Thomas lets out a sigh of defeat. "I'll come back for you..." He mumbles. Thomas runs down another hallway while Talyn rests their face on their lap, curling up into a ball.

As Thomas runs, the singing starts again. Thomas gasps as he spots movement out of the corner of his eye, causing him to hide as the two Gems who captured him and his friends walk by. "We can't leave yet!" Thomas peeks around the corner to see the poppy topaz and the howlite passing by. "The whole point of coming here was to check on the Cluster!" The poppy topaz exclaims. The howlite punches the wall next to the cell of where the singing was coming from. "Stop singing!" The howlite yells before turning to his partner. "Sunstone takes priority. Get back to the bridge and set a course for Homeworld."

The poppy topaz turns and walks back. "'Go to earth,' they said. 'It'll be easy,' they said." They grumble. Thomas turns the corner and sees another gem, a red moonstone with his gem embedded in the back of his left hand, in a cell. The Gem looks around, making sure it's safe, then starts singing again. Thomas approaches the cell. "Hey, I like your song. Are you Roman?" He whispers "You escaped..." The red moonstone mumbles. Thomas, not hearing him, reaches through barrier, creating a gap for the trapped gem to escape. Thomas shakily smiles as the moonstone steps through.

In the distance, the sound of the onyx calling for Roman catches the monstone's attention. Without a word, the moonstone grabs Steven's hand and runs at an incredible speed, pulling him along. They stop at a doorway, the moonstone dropping Thomas' hand, looking through a room with the onyx on the other side, who gasps upon seeing the moonstone. "Virgil!" The two run, meeting in the center of the room, embracing each other. "Did they hurt you?" The onyx, Virgil, asks, scanning the other for injuries. "No, no, I'm okay. Did they hurt you?" Roman fires back.

"Who cares!?" Virgil exclaims as he starts tearing up. "I do!" Roman kisses Virgil tears away. Virgil picks up Roman and spins him around. As they spin and laugh, their laughs overlap each other and they fuse, becoming an amorphous white blob of energy that then becomes a being named Bloodstone, who lands in front of Steven. The laughing switches to a very familiar voice just before he lands. "Thomas! Thank you!" Bloodstone exclaims. "Bloodstone! You're a fusion!?" Thomas exclaims with a gasp.

"Aw, I'm sorry. We didn't want you meeting us here like this." Bloodstone says, an apologetic look in his three eyes. "Well, did I make a good first impression?" The young hybrid asks. "Oh, Thomas. We already love you." Bloodstone says, hugging his charge softly. Suddenly, a new male voice yells something. "It's that howlite. Thomas, find the others and get to the control bridge." Bloodstone says, nudging Thomas towards one of the doors. "But I don't know where they are..." Thomas says. Bloodstone kisses Thomas' forehead, allowing him to see where his other two guardians are.

"Future vision... Wait, are you gonna be able to beat him on your own?" Thomas asks, worried. "It's okay, Thomas. I'm never alone." Bloodstone says as he stands. Thomas nods and runs off. The howlite enters and faces Bloodstone. "Oh great. You're both out? And you're fused again? Why? Fusion is just a cheap tactic to make weak Gems stronger. Quit embarrassing yourselves! I've seen what you really are." The howlite sneers, causing the fusion to chuckle. "No, you haven't."

This is Bloodstone

Back together
And I'm never going down at the hands of the likes of you
Because I'm so much better
And every part of me is saying "Go get 'im."
The two of us ain't gonna follow your rules.
Come at me without any of your fancy tools.
Let's go, just me and you.
Let's go, just one on two.

Go ahead and try to hit me if you're able.
Can't you see that my relationship is stable?
I can see you hate the way we intermingle.
But I think you're just mad 'cause you're single.

You're not gonna stop what we've made together.
We are gonna stay like this forever.
If you break us apart we'll just come back newer.
And we'll always be twice the gem that you are.
I am made o-o-o-o-of
Lo-o-o-o-ove o-o-o-o-of
Lo-o-o-o-ove
Lo-o-o-o-ove
Lo-o-o-o-ove

As Bloodstone sings, he and Howlite fight, with Bloodstone mostly dodging the other's blows. While Bloodstone sings the chorus, Thomas finds Logan and Patton. Then, the three head into the control room. Thomas breaks Poppy Topaz's Gem Destabilizer while Patton ties them with his whip. "Don't touch that! You clods don't know what you're doing!" Poppy Topaz yells. "You got this, Logan!" Patton exclaims, ignoring his captive. "Okay, ship. Turn us around!" Logan reaches into the ships control panel, his eyes flash with lines of data.

Thomas glances at the ship cam and sees Bloodstone and Howlite fighting. The two continue fighting, with many more hits actually landing. Howlite then spin dives at Bloodstone and causes both of them to fall through the deck and into the ship's engine room. Bloodstone stands up, obviously buffeted by Howlite's last attack.

This is who we are.
This is who I am.
And if you think you can stop me
Then you need to think again.
'Cause I am a feeling
And I will never end.
And I won't let you hurt my planet,
I won't let you hurt my friends.

Go ahead and try to hit me if you're able.
Can't you see that my relationship is stable?
I know you think I'm not somethin' you're afraid of.
'Cause you think that you've seen what I'm made of.

But I am even more than the two of them.
Everything they care about is what I am.
I am their fury.
I am their patience.
I am a conversation.

I am made
O-o-o-o-of
Lo-o-o-o-ove o-o-o-o-of
And it's stronger than you.
Lo-o-o-o-ove o-o-o-o-of
Lo-o-o-o-ove
And it's stronger than you.
O-o-o-o-of
Lo-o-o-o-ove o-o-o-o-of
And it's stronger than you.
O-o-o-o-of
Lo-o-o-o-ove lo-o-o-o-ove

While Bloodstone sings, he continues to fight with Howlite, once again dodging many of his attacks. Finally, Bloodstone catches Howlite and throws him into the ship's main power source, causing it to explode. Thomas, Poppy Topaz, Patton, and Logan are jostled by the explosion. As the ship rapidly descends towards earth, Bloodstone runs down the hallway towards the control room while still singing. Poppy Topaz crawls away, hitting their head against the deck to activate an Escape Pod, which they then escapes towards Earth on. Patton jumps to try and stop Poppy Topaz but fails, falling flat on the ground.

Thomas, Patton, and Logan look out the window as the ship continues its freefall. Bloodstone finally enters the control bridge. "This ship is going down!" He exclaims, hurrying to get everyone off. "What about Talyn?" Thomas asks. "There's no time!" The fusion exclaims. The aforementioned rainbow tourmaline is looking forlorn, still locked in their cell. The ship lands on the hill where the Crystal Temple is. The ship explodes as a lion comes running down the beach before blasting the rubble, revealing Thomas and the Crystal Gems in Thomas' bubble.

"Nice one." Bloodstone mumbles. Immediately, Thomas turns around, stars in his eyes. "Oh my gosh! I can't believe you're a fusion all the time!" He exclaims. "You met Roman and Virgil?!" Patton exclaims, stars forming in his eyes as well. "Oh no! We were going to introduce you. Bloodstone, your plan!" Logan frets. "We were waiting for your birthday." The fusion explains to the confused hybrid. "We can still do it! I'll just pretend I didn't know!" Thomas exclaims, causing his guardians to chuckle. Suddenly, a hand reaches up through the rubble. Howlite emerges from the burning wreckage of the ship. He attempts to stand, but falls to his knees. "Don't think you've won. You only beat me 'cause you're a fusion! If I had someone to fuse with I'd--" Some rubble shifts, cayaung Howlite to stop talking and look in that direction.

After a moment, Talyn emerges from the rubble. They fall to their hands and knees and attempts to flee, but Howlite grabs their leg. "Come here, brat! Aw, don't fly off so soon." Howlite sneers. "Talyn!" Thomas tries to run over to the rainbow tourmaline, but Patton and Logan stop him. "Talyn, listen, fuse with me! How long did they keep you trapped here on this miserable hunk of rock?" Howlite drops Talyn, causing them to groan as they got the hardpacked sand. "These Gems, they're traitors to their Homeworld. They kept you prisoner. They used you. This is your chance to take revenge! Come on, just say yes." Howlite holds his hand out, waiting for the other to take it.

"Talyn, don't do it!" Thomas pleads. After a moment, Talyn's face hardens and they take Howlite's hand. The two dance and turn into an amorphous white blob of energy. Spinel, a fusion of Howlite and Talyn, appears from the blob of energy with a cackle. Spinel raises their arm, summoning an arm made of water from the ocean. Suddenly, the arm grabs their arm and becomes a shackle. "Huh?" Another arm emerges from the ocean and takes Spinel's other arm, also becoming a shackle. "What?!" Water chains appear and wrap around Spinel's torso and neck. "Ughh!" The water starts dragging Spinel into the ocean. "What are you doing?!" The giant fusion yells in Howlite's voice. "I'm done being everyone's prisoner. Now you're my prisoner!" They respond in Talyn's voice. Two more water-arms grab Spinel's back legs. "And I'm never letting you go!"

The arms pull Spinel into the water until only their face is visible. Spinel's face briefly splits into Talyn's and Howlite's. "Talyn!" Thomas cries. "Let's stay on this miserable planet... together!" Spinel exclaims in Talyn's voice once more before disappearing into the ocean. The team stands in silent shock for a couple minutes. "Yikes. They are really bad for each other." Bloodstone mumbles under his breath. Thomas' phone starts ringing. Thomas fumbles to pick it up before slipping it next to his ear. "Uh... hello?" He says. Through the phone, the sound of his best friend, Jon's voice speaks. "Steven, I got your message. Are you okay? What's going on?" Jon asks, really concerned. Thomas doesn't respond, still shocked about everything that has happened in the past six hours. "Thomas... ?"

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Anyone who can guess who Poppy Topaz correlates with in Thomas' friend group gets an internet hug!! Also this is what Spinel's gem looks like.