Content Warning: warning for self inflicted injuries on a childs body and blood.

Good Night, Good Night

Four months had past since Yuuji came into his life. At first he wasn't sure what to do with the kid, even thou they had gotten along the first few days, the weeks that followed were filled with uncertainties. There were times Yuuji would be a joyful little sunshine, jumping wall to wall with excitement as he tried a whole lot of new things, from toys to foods to different experiences. He even enrolled him in a daycare just a few blocks away from his place which was the best and probably hardest decisions he has ever done. Sure having Yuuji recount his day and what he's learned excitedly is one of his days highlights but letting Yuuji be on his own without him was tough to handle, it took several weeks of him calling multiple times a day to check on Yuuji to finally get reassured that nothing bad will happen to him that he finally breathed easy.

However, despite the ups Yuuji has there were times he would be completely silent and still. Satoru loathed those days since they were followed by nights filled with nightmares that plagued the young boys sleep. On those nights when he holds the frightened child in his arms, feelings of complete powerless would grip him like mad.

He tried asking Yuuji what haunted his dreams and about his past, where he came from and why were they on a run buf the boy would only keep saying to not take him back to 'that' woman. The white haired sorcerer tried to prod for more but Yuuji would immediately clam up and end up in more distress, up to which point Gojo gave up on getting any answers from the kid. It wasn't worth sending Yuuji in to panic. Who ever that Woman was, if ever he meets her he promised that there'll be no mercy from him.

Another thing that contributed for the uncertainty he felt during those first few weeks was the appearance of the King of Curses. Thinking back to that day always left a vile sick feeling deep in his gut.

Satoru knew immediately what was residing within Yuuji upon their first meeting. He had felt that presence before, back when he was in his first year where they were shown one of the cursed object incase any of them should encounter it in their assignments. Despite being wrapped in a thick layer of seals and stored in a room covered in talismans, the icky and pungent aura it gave of was something he could never forget. He felt it in that room and again in the forest where he found Yuuji though that time it was a bit muted and now there is certainly no mistaken to whose presence it belonged to. Not when the main source of it was standing in front of him wearing Yuuji's features. The sharp red eyes, hair combed up and dark marks that covered the boys skin was all wrong. For almost a second Satoru didn't know what to do but before he could get over his shock he had subconsciously activated infinity and his cursed energy was thrumming in the air, instincts taking over at the presence of danger.

The child, which was not Yuuji gave him an unimpressed look, bored almost as he slowly sat on one of the couch. He crossed his legs and rested his cheek against his fist. Gojo blinked. What.

"Che, you humans jumping in to action at the first sign of danger."

"What did you do to Yuuji." Satoru demanded, he was already standing ready to defend himself if the other struck.

"I said where's Yuuji." he repeated when the the other didn't gave him a reaponse. He was busy glancing around his surroundings to pay attention to the Sorcerer in front of him.

"I heard you the first time Sorcerer. The brats asleep. Now sit down."

"The hell will I listen to you." the other rolled their eyes and slid something out from the pocket of Yuuji's Pajamas. It was a knife. The teen stiffened when the other brought it across their own throat.

"If you don't listen, I'll slit this boys throat. He's not gone just deep asleep right now. So take your pick, sit down or I'm gonna fucking drag this knife across his throat and have him conscious for it." they threatened, Satoru hesitated but when the other pressed the blade and beads of blood sprouted he immediately took his sit.

"Good. You will make a binding vow with me."

"What— there's no way I'll make a vow with you, especially from the king of curses himself." Satoru gritted his teeth, he didn't know what action to take without putting Yuuji in danger, hell he doesn't even know how to rid him of the curses presence.

"I have no power right now. If you were any smarter... Well if you'd used those eyes of yours for what's it meant ot just a pretty accessory, you would have seen it by now." Gojo stared at the being in front of him, no power? He paused, Now that he'd calm down and gathered his wits, aside from the unmistakable presence of the king, there was no cursed energy radiating from the boys body.

"I'm no threat right no but I assure you when I get my hands on my other fingers I will raze the earth to the ground." Sukuna gleefully admitted.

"Why do you want a binding vow for?"

"To ensure the preservation of my vessel, why else."

"Your vessel!? Yuuji's no—"

"Oho ho, that's where you'll be mistaken. This body is mine, made to house me and bring about the new age of destruction, however as you can see the body is still young.

"Then find another body," spat the teen. The curse glared at Satoru before he sliced a long line across his forearm, blood began to spill and Gojo immediately jumped to his feet.

"Sit down." Sukuna ordered but Gojo remained standing.

"If you want another cut on him be my guess." Gojo say back down. "When I say sit down, you sit down and when I say you listen, you listen" Sukuna sneered.

"As I was saying, the boys body is still young and one finger isn't enough for me to take control of this meat suit nor use any of my powers. I'll need more of my fingers—

"I'm not collecting them for you."

"You don't need to and that's not what I need from you."

"Then what do you want?"

"You just have to protect this vessel until he's grown enough to properly host me." Satoru let out a bark of laughter, the curse can't be serious.

"That's— why does the great and powerful King of Curses, Sukuna Ryoumen, seek protection from their sworn enemy?" the teen spat.

The king sighed and before Satoru could move, he brought the knife up and quickly slashed it across the boys throat. Satoru stared in horror as blood began to gush from the wound, splashing against the seat and wall. The king of curses grinned maniacally at the others stunned reaction.

"Ah-ah," Sukuna warned.

"Protect my vessel and in exchange I'll heal his wounds. I can always let him die off. It would be a pain to look for another one since this one is perfect but I'll manage. That wrenched woman— if I could call it that will try and have me incarnated again either way if this body gets killed off but I'd rather not have anything to do with her."

"I'll do it." Gojo spat. Sukuna laughed before jumping off the couch and walking over towards the wide eyed teen. He brought his blood stained hands and patted Gojos cheek causing blood to transfer against the teens pale flesh.

"Good." Satoru didn't flinched when the other made contact with him instead he stared directly at those deep crimson pools.

"You got guts kid, how 'bout this as a bonus, I'll stop manifesting for a while' til ofcourse the brats been expose to your world, when he gets embroiled again in jujutsu that's when I'll have my come back."

"Wha—"

"You'll fail you know, at keeping him ignorant of this world." Sukuna mocked, "he was born in to this, this world of ours will find him and drag him back for me to consume.

"Mah~ aren't you worried that I might find a way to prevent you from taking over while you take your nap?" Satoru said trying to put confidence in his words.

"Hah, you can try and I'm sure it'll make a good form of entertainment at seeing you fail miserably. Now the vow." Gojo clicked his tongue but never the less held out his hand which Sukuna gripped. Once the binding vow has taken root the boys body fell to Gojo's arms, unconscious yet free of those black tattoo markings and most importantly the cuts have disappeared. Satoru let out a breath he didn't know he was holding. Yuuji stirred in his hold which made the teen winced, the wounds might have disappeared but the blood was still present. He'll have to clean Yuuji up and himself from it. And the couch and carpet as well. For now he was glad that Yuuji was okay but after the king of curses appearance he has more questions than answers. Who exactly was this mysterious woman that has even Sukuna apprehensive.

Satoru was knocked out of that unpleasant memory, literally, when Yuuji ran up to him in a hug.

"Sato-nii I'm done with breakfast, can we go now? Sensei told me yesterday I was gonna lead today's song!" he said.

"Ehh! Your leading I wanna see Yuuji-kun singing!"

"You can't! You said you have school, you'll be late too."

"But I wanna hear you sing." Satoru fake cried which made Yuuji puff up. The boy crossed his arms and frowned at the older teen.'Ah Yuuji's so cute when he's trying to be stern' Satoru thought.

"I'll sing for you later, Sato-nii was the one who said school was important."

"Ahh I did say that, didn't I? But that doesn't apply to me, I'm Gojo Satoru, I don't need school."

"Ehhhh if you're not going to school then I won't too."

"That's okay, we'll just stay at home and eat cake while you sing."

"Won't your sensei be mad?" Yuuji pointed out and he was right, Yaga-sensei might find him and beat him up again.

"Fine." Gojo pouted but Yuuji didn't paid mind to it instead he grabbed Satorus hand and drag him towards the door to which Satoru willingly went along.

'I'm going to keep Yuuji safe. I promise. You can go ahead and try Sukuna but I'll do my darnest to keep you from taking over Yuuji.' Satoru vowed to himself. There's still plenty of time yet for Yuuji to grow up meaning theres still time for him to make plans against the King of Curses.

To be continued~

Omake #1

Yuuji: That's the 17th one, 3 more to go

Satoru: About that—

Megumi: What does that mean!!?

Sukuna in his inner domain: *laughing maniacally*

Omake #2

Yaga: Why were you late?

Gojo: I got kicked out of a daycare

Geto: Why were you in a daycare?

Gojo: Uhhhh

Iieri: I think we don't wanna know, you creep.

Gojo: It's not what your thinking!

Gero: That's what they all say.

Yaga: *cracks his knuckles*

END NOTE:

Originally posted on ao3 under my username Vividly_Violet.

You can also find me on twitter @Vividly_Violet_ and on tumblr @violetlou2020