Avengers x reader //The girl that stole their hearts

The uninvited guest

3rd person POV

Everybody at the party hears an extremely irritating high pitched ringing noise then out steps some form of creature made of wires and even has an avengers symbol on its chest. Y/n immediately senses something is up and quickly ushers everyone who is not able to fight out of the room so it's only left with a couple trusted S.H.E.I.L.D. agents and the avengers + Loki, Jack & y/n because they technically aren't avengers yet even though they really wanted to be but there was a feeling inside Y/n telling her that she wasn't good enough. A killer shouldn't be an avenger.

The creature filled with wires trudges in and the room and looks at everyone, the thing says "how can any of you be worthy? You're all killers" referring to those who couldn't lift the hammer. Everyone is in just as much shock as I am, Steve says "Stark?" Tony quickly says "JARVIS?"

The creature begins to apologise for killing JARVIS but I can tell he's definitely not sorry. Steve says "you killed someone?" The wire thing says "wouldn't have been my first call but in the real world we are faced with ugly choices" Thor asks "who sent you?"

The robot thing plays a message that sounds like Stark, bruce exclaims "Ultron!" The thing I presume is called Ultron says "in the flesh, or no, not yet. Not this chrysalis" I pick up Thors hammer and give it to him "ah! I see, one of you is worthy. Y/n y/m/n y/l/n, kidnapped by Hydra at age three. Tortured, beaten and experimented on. Was it 5 times a day" I stare at him straight in his robotic eyes and say "6". Which makes some people's eyes soften then the stupid thing starts to talk again.

"Okay, 6 times. You're the dark angel. Killer of men. Ballet dancer. Smartest 22 year old on earth so I hear. You certainly don't look like it" The ugly thing said which made everyone shocked at the smart sentence then clench their fists at the last. "Look here you scrap metal piece of shit. I don't know what the hell you are fuck face or what you are doing here but you better shut the fuck up before we all kick your metal ass."

Everyone in the room was trying to hold in their laughter and even Loki from the corner of the room raises his eyebrows and smirks, then the thing speaks "oh and she talks too. Let's see how smart you are then, can momentum be hidden to human eyes like how kinetic energy can be hidden as heat?" 

Everyone looks baffled apart from Bruce and Tony who were trying to work it out, "Easy, Yes and no. In a regular mechanical system with macroscopic parts, momentum can not be 'hidden' to human eyes. But in other systems, momentum can be hidden. For instance, in an electromagnetic system, momentum can be transferred to the electromagnetic field, which is invisible to human eyes at most frequencies. Therefore, momentum can be 'hidden' in the electromagnetic field. Boom bitch"

Everyone stands there gobsmacked, even Tony and Bruce. "Pretty smart for a girl who looks like she could either kill you or trips over her own feet", I crack my knuckles and say "take a wild guess."

The thing does a weird robot smirk and says "fine, another question. Does the negative mass of an antimatter mean that it's gravitationally repelled from stars?" "You've got to stop asking me these easy questions metal mouth, antimatter does not have negative mass. In our universe, there is no such thing as negative mass. Mass only comes in positive form. In contrast, electric charge can be positive or negative. 

The nonexistence of negative mass has profound consequences. First, gravity is always attractive and never repulsive. Presumably, if negative mass existed, it would be repelled by objects with positive mass such as the earth or sun. A cup made out of negative mass would fall up and not down when you let it go. As interesting as this sounds, negative mass does not exist, so heavier objects always fall down. Second, the lack of negative mass means that gravitational fields can never be shielded, blocked, or canceled. In contrast, electric charge comes in both positive and negative varieties. An electric field created by a positively charged object can therefore be blocked by a wall of negative charges. This is the principle used in metal shielding, which keeps the microwaves in a microwave oven from cooking everything in the kitchen. But there is no negative mass to cancel out gravity. If negative mass did exist, you could use it as a form of anti-gravity. If you built a floor on earth out of negative mass of sufficient size, then people above that floor would feel no gravity and would float around. Again, negative mass does not exist, so genuine anti-gravity is not possible. Gravity permeates every cell of every creature, and into the deepest dungeon with the thickest walls. Happy now?"