A/N: Hello anyone reading this, i'm just a dude writing at 3 in the morning and had a great idea to make a Warhammer 40k/Steven Universe thing, I don't know why, they have few and far between similarities and two very different fan bases but i'm some weirdo who loves both with all my heart so I wrote a thing. I have never written before on this site so leave a review if you would be so kind telling me what you think about it, updates will bereal regular if I get like any feedback. If you would like to learn any back story on Warhammer 40k which is not really required to understand the story but certainly ups the cool factor the, Warhammer40k wiki is godlike level good and you can just search up info if you want. Small notes, while this is pretty much a Crossover i'm not putting it in the crossover section as its only the one character, I don't know how the rules are done around here but I would rather SU fans read and see this than it be obscured behind a different page. Also the first short portion of the story is more or less a small recap of Steven and the Stevens. Happy Reading (: - Disclaimer stuff: I do not own Steven Universe or Warhammer 40k, the story is a piece of fiction that is not official to either brand, purely fan fantasy.

Chapter 1: An Alternate Path

A scene of destruction was all about the mangled Emperor, the bodies of a hundred warriors, human and transhuman alike were strewn about him, the mighty Astartes Marines and his own Adeptus Custodes made up the piles, metal rent and torn, limbs scattered, his own body a ruin of its former self from the wounds inflicted on him by his wayward son, empowered by the foul energies of chaos that were controlling him he was unassailable by physical means. His lightning claw hovered overhead, promising swift death, only the complete destruction of his soul would bring about an end to him. The Emperor still struggled to find his will to do it, powerful and mighty as he is, or at least was after this final act, he was still human, however hard it was for his subjects to believe. At this last moment as he rose to unleash his mind, to rip Horus from the hold of chaos and end it, he saw a change in the weave of fate, a pink rift opened in the warp aboard the ship as he began to strip his son of his power, with it gone he was finally revealed, Horus Lupercal, Primarch of the 16th Legion and former Warmaster of the Imperium looked up at his father in shame and horror at his actions while he was being manipulated by the dark gods of the warp. The Emperor saw his son pure and untouchable as he was meant to be and could not end him, he was not yet lost, he threw his son at the rift. Whatever would be his fate, it would not be death as a pawn of the forces of chaos, it would be as a noble paragon of humanity, valiant and defending its future, guiding it, free and unthreatened. Whatever multiverse he arrived at, he would follow his quest at redemption.

"How about this one here?" inquired a curious Steven as they walked the halls filled with sand and hourglasses. He stood over a round glass with gold edgings .

"What one?" asked Pearl walking to him through several floating ornate glass-works.

"This little one, it's ador-bable" he said with stars in his eyes looking to her for permission to choose it.

"Steven, the legendary Glass of Time won't be nearly so small and insignificant, it would be beautiful and grand, like this one." she said with her hands together and eyes beaming looking up at a large hourglass with much more extravagant gold edges and vine like ropes at its sides. Toward the middle of the shrine Garnet stood looking up at the large centerpiece in the middle of the room, a massive hourglass.

"I think it's this one." she said with some certainty sounding in her voice.

"Woah." Steven said as he saw the centerpiece of the shrine while he walked over with Pearl, looking up at it.

"You mean the biggest one? How are we even supposed to get that back to the warp pad?" she said questioningly.

"I can carry it" the reddish hued gem answered, cracking her light based knuckles in preparation for the lift.

"Wait" said Pearl putting her hands on her Garnets shoulder, "We need to be careful which one we touch, you remember what happened last time we were here." she said frowning.

"What happened" asked Steven.

"Hey guys," sounded the lilac colored gem across the room " I'm making the call, it's this janky looking one here!" said Amethyst proudly holding an hourglass of random shapes.

"Amethyst!" gasped Pearl as the room began to shake violently.

"Uhhhh nope it wasn't." said Amethyst looking down at her faulty choice. The top of the dome overhead shimmered and dematerialized allowing the water above them to cascade down into the shrine.

"Look out." said Garnet as she nabbed an unsuspecting Steven and rolled out of the waters way. "We don't have much time" she said to Pearl crouching next to her.

"Amethyst come on." Pearl yelled to her, without warning Steven bolted from the safety of Garnet's arms. "Where do you think your going." she exclaimed. The boy turned around quickly.

"Amethyst gets to keep hers." he said pointing.

"Darn tootin." shouted the gem as she passed him by with the twisty hourglass in her arms.

"I'm gonna get the one I picked out" he said as he sprinted away to the back of the shrine.

"Steven" they all cried out in unison, the boy ran back to grab his prize, and for whatever twist of fate, here the story diverged, he instead grabbed a closer prize, a red tinged glass of the same size but square and thick. Sprinting back into Garnet's arms, she gave him a pat on the head and they warped just in time to only almost avoid being assaulted by all the creatures of the sea who were now sprawled across the floor of Stevens home.

Water logged, the trio stood and stared at him for his recklessness, which they were always ready to forgive after his trademark smile. The real fault was on Amethyst who was now being scolded by Pearl who instead tuned her out and began making a sandwich.

"I wonder what kind of magical glass you are" Steven said looking deep inside to its slowly shifting sands, it seemed to shimmer at his words but he swiftly pocketed it as another thought burst into his head.

"The Beachapalooza!" he exclaimed with no apparent meaning as he scrambled to find his helmet and bike.

"The beach-a what?" asked Amethyst as she walked about the waterlogged floors.

"Beachapalooza." corrected Garnet.

"Dad promised me he would be in a band with me to perform for the town!" he said happily as he stepped out the door.

"Thats nice Steven." said Pearl absent mindedly, poking and studying the glass Amethyst picked, "Be back in time for dinner".

"Ok, bye." he said as he blew a kiss and flew out the door, upon getting outside he saw it was already much later in the day than the gems said it would be by the time the mission would be over." Aw crud, how am I going to get to dads by in time so we can organize this rockin band?" He said to himself, " If only Lion was around I could get him to warp me a portal". As he thought about how to best find that elusive feline he felt a warm glow in his pocket, pulling out the square glass he felt it humming a low vibration. Realizing his last few words he put two and two together. "Can you get me a super fast interdimensional portal to my dad's little buddy?". The instant the request was put in it exploded with power and shimmering light sucking the boy into its veil.

As he flew through a seemingly endless torrent of windows and doors into different places Steven plummeted into void, looking frantically for anything that looked remotely like his father's car wash he began to panic and reached out to the portals in the bright chasm he was falling through. He neared on that he was going to touch but instead looked inside quickly, he saw a dark form being thrown toward him, and an old man, tired looking and tall, in golden armor and looking him in the eyes, he was injured badly but had a look on his face of almost, relief. Bright colors of pink and purple swirled around him as the very bulky form crashed into him. He looked up at the man whose leg he was now holding on to for dear life, he was wearing a dark metal suit of armor that encased his whole body, the design was nothing like the armors he had seen in Pearl's room and seemed to thick to even be able to move. Content not to tumble forever and horribly confused Steven reached out and touched the nearest portal he could and he and the man were surrounded by light. They materialized on in the air over the beach a few yards away from his house.

Steven saw it in is vision as he tumbled through the air. "Far" he thought, as the wind whipped around his ears, "We are too far up" he was yelling in his mind and then just yelling incoherently in general as the ground rushed toward them. He looked up to see the sharp angled face of the man who had smashed into him as they fell, looking down at him Steven's world shrank under his gaze, his bald head and defined features burned with intensity as he observed him while falling. Suddenly seemingly aware of their situation he quickly took the child in one massive armored hand, more than the size of Stevens torso. And shifted in the air with more grace than he had ever seen from Garnet or Pearl to adjust for the impact feet first, they hit the sand with a booming thud and Steven was lowered onto the ground as the man collapsed to his knees, not from injury as he seemed just fine physically, taking the fall with nonchalant ease.

The man began ripping the armor from his flesh, great chunks of metal were torn with his bare hands and plates were thrown off of him, "Disgust" thought Horus, armor stained with blood, the blood of his Father, he threw it off of himself and finally discarded the large claw on his right hand, nearly the length of a full grown man and coated in blood. He was free of the prison of metal at last, the armor was a sick parody of his former regal garment representing his Legion, the Sons of Horus, twisted by chaos and made evil, he discarded it. He was in a thin, plain grey uniform now, a basic overlay for the suiting of his power armor, naked without its covering but free of its choking insides. He knelt on the beach looking over the foreign body of water, He had betrayed them, all of them, his brothers, his legion, the empire and his father. He was a puppet for the destruction of billions of lives and for what? His Father should have ended him, but instead he spared him to, wherever he was, where was he? He looked down to the child he had collided with most normal humans sat dumbfounded when confronted with the sight of a Primarch on the best of occasions, a son of the Emperor of Mankind, a giant, a figure of unprecedented charisma strength but this one seemed more curious than anything. He looked down to the stocky child with a bright yellow star on his shirt, an emblem of his clan perhaps? He was unsure were he was and more unsure as to why the child was falling through the warp. Looking up to him with bright eyes and confused features.

" Um, hi, my name is uh, Steven." He said standing up, still only reaching the Primarchs elbow as he sat " I don't suppose you travel by inter-dimensional portal often?"

Humor, thought Horus silently still looking at him, that was an uncommon reaction, he would have been tempted to laugh but the gravity of his previous situation was still fresh on his mind, still he needed information.

"I do in fact to do this often, though usually I know where I am going and am safe inside a ship, tell me child where did you acquire the means to get inside of the warp?" he said after a moment with a small smile, and worded it with enough gentleness to keep the negative emotion from his turmoiled thoughts out of his character.

"Oh, I usually go with the gems and they warp me places or on my lion but I can never find him WHEN I NEED HIM " he shouted into the darkness and looking around for any sign of it, a rather unsubtle signal for help thought, Horus but at least he now knew the child was intelligent, if a little insane, he knew not of these "gems" or what lion he was referring too, probably the rambling of a child who had been driven mad by the foul warp energies of chaos.

"You said usually, not this time though" Horus spoke with a commanding intensity, few could hide information from the intellect of a Primarch " Show me what took you into the warp child." The boy looked down at the sand and drew a small object out of his pocket and raised it to see.

"Its some important gem thing but I uh, I tried to use it to get where I wanted to go faster, I think it might be broken now" he said sadly gesturing to the thin cracks lining the edge, its use must have fractured it thought Horus, the warp was dangerous and powerful, too dangerous for a child. He swiftly and smoothly snatched it from the child's grasp. "This is far too hazardous for you to play with" he said

"Hey" pouted the boy,"that's not really yours to have and the Gems get really mad when humans find their stuff" he said trying to jump up to the Primarchs hand and grab it. That last part caught his attention, he looked down at the boy, whose strange references were starting to make more sense. Xeno's, thought Horus, the very thing he had spent the better part of his life exterminating, alien life threatening humanity's expansion of the stars. As if on queue voices shouted behind him

"Steven!" yelled a large woman of strange garment followed by a smaller one, rake thin and pale, dressed the in the same fashion and the most obvious giveaway and small purple figure of obvious alien origin, they were all fairly human in facial appearance but their heights and skin were clearly not. They all skidded to a halt just before him, the Primarch stood to his feet, his monstrous height even without his armor towered over the tallest one of them by more than a few inches. The boy to his side now realizing his size looked like positively puny next to the man. He stood keeping the boy behind him and leveling his piercing gaze to these "Gems" as they boy had said. He could see why immediately, each had a precious stone embedded somewhere. He left the jewelry and finery to his other more vain brothers like Fulgrim or Sanguinius but he recognized the cuts, a Garnet an Amethyst and a Pearl. Why they had these on them he did not know. They seemed suddenly aware of the object in his hand as they stared back at him in stark confusion and whispered among each other.

"Human" said the tallest dark skinned one " That glass is dangerous and should not be in your possession, please release it, and Steven." she said as calmly as she could but Horus saw past her tone, she was unnerved.

"Important questions first, what are you and why are you on this planet." he said not quite willing to heed to this foreign woman's demand.

"We are the Crystal Gems." she said with pride and authority, "We are the guardians of this planet."

"Which planet would that be?" he said twirling the small object in his hand much to the annoyance of the dark skinned gem.

"You not from here or something pal?" said the smallest one with a chuckle.

"No." answered Horus with zero sign of amusement.

The sturdy expression worn by the gems now dropped to a state of shock, "This planet, The planet Earth". Said the thinnest one

Nonsense, thought Horus, though earth was an old term for it, for the wider imperium called it Terra, humanity's home planet, they could not have been on it. Horus WAS just on it and it looked nothing like this, no war, no sprawling cities that stretched continents. Any masque of calm Horus wore was gone, the anger of a primarch was a thing known to shake worlds and this situation was no exclusion, the gems in his malevolent gaze all felt the change in atmosphere as he spoke.

"You lie" he spat "I just was on earth, this is not it, and no earth I had come from had xeno's guardians. Who are you and why are you in possession of this device, why does a child have it?" he said with a venom that threatened violence. The gems had clearly had enough.

"Stay back you two." said Garnet to her companions as she strode toward him, "This does not have to resort to violence, you seem confused and we can help, just give me the hourglass."

"Move away child." he said to the boy

"Go Steven." Garnet said coolly, He ran to the two gems behind her and stood next to them, Horus was beyond reasoning at this point, he knew only anger, they planned to trick him, agents of chaos sent to reclaim him and chain him to their bidding again, she moved first.

Lightning fast movement raced to his arm as she sought to snatch the object, did she think him just a weakling not even worth confronting? He imagined on this lone planet she had only normal humans to contend with, he would use this to is advantage, with an equally lightning fast reaction he grabbed her wrist and twisted upward using her momentum he yanked her savagely to the side and picked her up over his shoulder and threw her, hard. A Primarch was human in the barest sense of the word, faster than most can comprehend and powerful beyond reason they were the greatest warriors known to have ever existed, even without his powered armor, which enhanced his power many times more at the cost of precious little speed, this was child's play, she tumbled across the sand and abruptly slammed into the rock face behind her companions as they gasped, Garnet herself was confused beyond belief, when she looked into the possibilities she saw this man's outcomes were a shrouded darkness and chose to face him if only to get Steven out of harm's way but no human had ever been the equal of a gem in speed and reflex, much less superior, she was enraged, if it was a fight he wanted it's a fight he would get, she summoned her gauntlets.

Charging back to him and blinding speed they began to trade blows assessing strength, she unleashed a crushing barrage of blows to the humans side which he blocked with blinding speed on his forearms, any normal man would have his ribs crushed in several places right about now but he seemed pleased with her assault, a smile crept onto his face, Garnet realized her error, she was wide open, he struck with speed Garnet had never seen, several hits rocked her torso before a crushing blow to the side threw her off balance and she stumbled back. Seizing this opportunity he unleashed a low sweep to the legs of such martial prowess that even Garnet, a warrior of thousands of years of battle was unprepared to combat, fully suspended in the air she crashed to the ground, he loomed over her and picked her up by the throat, gems needed no air but she felt him squeeze hard enough to pop the head clean off of a mortal man.

"Why would you be a guardian of the earth you say this is, why would an alien be defending humanity's cradle world, who are you really?" he asked her refusing to believe that he had somehow been thrown out of his timeline, his reality even, the more he looked the more evidence he saw to his fears, the moon in the sky, the stars in the same places, the human boy, he was grasping at nothing at this point, only his own rage. She used this moment of confusion wisely and thrust her powerful legs to kick him away and free herself from his grip. She landed a safe distance and resumed a very staggered and wounded fighting stance. He looked around him, the evidence was there as he made out each star visible from earth's orbit, he saw a human settlement in the distance, lights and homes, He recognized some of the signs from old pictures of earth's most ancient history, he was in old Merica as they knew it in the imperium, one of many states and countries existed during earth's developmental period before the terran crusade launched by the Emperor. He looked to the child, in the distance with fear in his eyes, he was frightened, from the way the thin gem had hugged him previously when he ran to her they obviously had some amount of caring for the boy. He was meant to guide and protect humanity, to lead it, he had betrayed everything humanity had worked for and doomed the empire, he did not want to repeat this, a cycle of anger, hate and mistrust in his father, wars that claimed lives by the billions, he was ready to listen to these xeno's, if there were truly humans here, he wanted to protect them not, to save them from the powers that had took his mind. He lowered his fists, and looked to the gem in front of him.

"I require an explanation as to how I was brought here." He said, palms extended outward, calmly and slowly lowering, as to de-escalate the situation he had created. "If this is truly Earth, and you are truly its guardians, then we serve the same purpose." She nodded after a moment and dissipated her gauntlets into a shimmering light.

"I knew you would see reason" said a calm voice behind him, he turned to see a very giant woman, with a very large boulder, poised over his head.