Couldn't resist writing this adorable headcanon! The concept is that Blake has nightmares from killing Adam but Yang is there to comfort her and let her know that everything is okay.

"No one hurt me quite like you."

"She made a promise to me once, that she'd always be at my side…and look how well she's kept it."

"So I just wasn't good enough for you."

"What does she even see in you?!"

She's at that moment again. She's standing there and her broken Gambol Shroud is lying on the ground in front of her.

He does too.

They're running for her sword. She has to get it first before he does. She has to.

And then all she sees is red.

And then he's falling over the cliff and into the water.

But then he's reappeared beside her, blood trailing out of his mouth and his stab wounds, glaring at her

Why must you hurt me like this?

You killed me, Blake.

Her scream startles the team awake. Weiss is reaching for Myrtenaster and Ruby is looking around for the would-be intruder, but Yang knows.

She's the first to kneel down beside Blake's futon, hugging the visibly shaken girl and whispering comforting words into her ear. She signals to Ruby and Weiss that everything is okay and that she'll take care of Blake so the pair go back to sleep.

"Hey, it's okay. You were having a nightmare. He's not here anymore. It's over now, Blake. He's gone. He won't hurt you anymore." Yang starts stroking Blake's back slowly.

Blake grasps desperately onto the back of Yang's shirt, trying to calm herself down. In between sobs, she replies, "We…didn't have to...It didn't have to end like that…We- I killed him, Yang. I didn't have to kill him. There could have been another way. I'm a murderer just like him." The tears start sliding down her face, pooling onto the shoulder of Yang's shirt.

Yang tightens her hug. "No, you're not like him. You're nothing like him. He wasn't going to change. You and I both heard him, Blake. He made his choice. He was just going to keep coming after us. It had to end one way or another." Yang lets go and leans back, bringing her hand up to cup Blake's cheek. She wipes the tears running down Blake's face with her thumb as Blake sniffles, her cat ears still flat against her hair. "I…I know what it's like to have these nightmares…but it'll work out, I promise. We can get through this together. You have me and I have you."

Blake finally looks up at Yang, her sobs having slowed for the moment. "Do…do you mean that?"

Yang nods reassuringly. "I'm here for you. Whenever you have nightmares, whenever you need to talk, whenever you need help, I'll be here. I'll be here as long as you need me to. And I know you will too." At this, the tears start welling up in Blake's eyes again, startling Yang. "Bl-"

Blake wraps Yang in another hug. "Th-thank you…" Blake mumbles between her sobs. Yang smiles warmly and reciprocates, as Blake continues to thank her. Yang continues stroking her back, letting her release her pent-up grief and stress from the fight.

When Ruby and Weiss wake up the next day, they have a brief moment of panic when they don't see Yang's futon anywhere. But Ruby is quick to spot her older sister, nudging Weiss quietly and pointing out Yang's new location.

Yang's futon had been moved at some point to be beside Blake's. Blake is fast asleep with a small smile on her lips, the fear and anxiety she felt earlier along with the tears she shed long gone. Her body, pulled in by Yang's arm, is pressed tightly against Yang's sleeping form, who also has a peaceful smile on her lips.

True to her words, any future nights that Blake has nightmares about that day, Yang is there beside her to calm her down no matter how long it takes. Some nights, they stay up to talk only to fall asleep as Ruby and Weiss wake up. Any time Blake needs her, even if she starts to break down during the day, Yang is there to wipe the tears away and reassure Blake that everything will be okay.

And in turn, any time Yang gets flashbacks to that night, Blake is there for her as well. She is there to hold Yang's hands and repeat her promise, that she won't leave Yang like that ever again. As Yang had said, these personal traumas and nightmares will take time to overcome. It won't be soon, but as long as they have each other, they know that they can do it.

And that's all that matters, somehow.

I didn't ask my friend to edit it because this was only ever intended to be a quick one-shot/drabble so mind any possible errors. Hope you enjoyed :D

PS I'm still working on Grimm Fairy Tales dw :P