Demon in the Frame (Male symbiote researcher reader x RWBY)

Chapter 1: Grudge Match

The two of you recompose yourselves and become one again.

(Liar) - WAS UNPLEASANT.

The two siblings look at you in fear of your newfound cruelty, as if they didn't expect this reaction after everything they had done for seven years solid.

(Liar) - Little lesson in extraterrestrial biology, kids! Symbiotes such as my kin and I are synthetic beings. We require a respiratory host to survive, and when we bond, for example-

Liar dodges Yang's punch, and extends six tendrils to knock Ruby away.

(Liar) - -Your 'Brother' and I, Our experiences are shared between the two. Every joy, every laugh, ...every AGONY!

Punches Yang, Ignores Ruby.

(Liar) - EVERY SCAR!

Ruby went flying, and Yang barely manages to hold her ground.

(Liar) - EVERY INJURY!

Attaches seven tendrils to Yang's head, lifts up, and brings her down HARD.

(Liar) - EVERY! HURT!

Yang is on the ground, struggling to regain her breath.

(Yang) - B-big brother... P-please...

Liar's chest opens up, revealing your face to your former sister.

(Y/N) - Shut up. You lost that right a long, LONG time ago.

Liar's midsection closes, once again hiding you. Liar grabs her by the hair and bluntly says:

(Liar) - You are nothing.

Yang's head is slammed into the floor, her aura being dropped to 3%. Liar recedes into you and you sigh.

(Y/N) - Now that that's over with...

You turn to Ruby, who looks more and more like a frightened child needing support from their mother or teddy bear. Tears pool in her eyes, and the camera closes in on the three of you just enough that they can see everything. ...But you don't care. After all that they did to you, she doesn't have a right to be cared about. Least of all, by you. She starts trying to slow your approach by throwing bits and pieces of her shattered weapon at you while desperately trying to crawl away. You remain unimpeded as Liar's tendrils catch each and every piece. Ruby finds herself unable to crawl anymore, and she watches you with both fear and tears in her eyes.

(Y/N) - You know, grudges can be powerful catalysts for a battle. You can't be more careful about invocation of such. ...We're not going to kill you. We're just going to make you feel every agony that you and yours had put us through.

(Ruby) - Wh-why are you fighting this hard? Don't- *sobs* don't we mean anything to you?

Your fingers reach her forehead, and before sending her down your memory lane, you reply:

(Y/N) - ...Nope.

(Ruby) - Wh-what?

Your calm demeanor dissolves for a moment. Long enough to let your verbal venom pierce her emotional mind.

(Y/N) - You thought that after all the torment, all those years ago, you would still mean anything to us? Well, prepare to have your eyes maced.

For Ruby, the next twenty seconds are an unbearable seven years of pain and suffering. When your fingers disconnect, she's left a gasping, blubbering mess.

(Y/N) - Were you really surprised? After all You and Yours have done to us? After so many years, and with so much more on my mind, You and yours STILL find the worst of ways to VEX US! Now I reiterate: I'm not going to take your life...