The red symbiote is slithering towards a new being. A being with powerful emotions that all thoughts of having anybody else is out of the question. As a life-form that depends on emotions to survive, this is a gold mine, and I must have him.
Izuku Midoriya just got told by his hero All Might that realistically, he can't become a hero without a quirk. Beaten down by everyone around him, along with his own idol… HURTS. The emotional pain is almost physical as he drags his feet through an ally. Out of nowhere, he accidentally steps in a puddle of some kind of green goo.
He thinks nothing of it and tries to shake it off, only for the goo to suddenly climb up his leg rapidly. Expanding tendrils, criss-crossing with each other now up to his hip, he beings to understand what is happening and freaks out.
Izuku screams in pure terror. 'This is the second time today that a slime monster attacks me!' He somehow comprehends, while trying to push away the progress the slime is making up to his chest now.
He realizes, just like before, he is powerless without a hero to save him. 'This is the end. I'm sorry mum.' Was his last thought before the tendrils wrap around his face and push itself into his nose and mouth, making him pass out.
The symbiote takes full control of his hosts body and relishes in the feeling. 'Its like an emotional buffet with no end in sight! Its almost to good to be true.' It thinks with glee. The symbiote looks through his hosts memories and almost laughs at how perfect of a match him and Izuku are. The symbiote wants emotions, 'honestly, the kid is almost hysterical. He can spare some for me no problem.' And Izuku wants a quirk, to become a hero.
'If the kid wants to be a hero, then a bloody hero he will become!' The symbiote is almost giddy from the emotions that he can feel through his memories, let alone what they feel like when they actually happen.
He wakes up his host and can feel his confusion.
"What the…" Izuku mumbles, just before thoughts not of his own are pushed into his mind. Not forcefully, and despite being scared of what's happening, he can honestly feel the satisfaction of the being that has claimed him.
'Perfect for each other'
'I'll eat away your awkwardness'
'We become hero's'
'I'm not leaving, so take it or leave it.'
In the span of a few seconds, the symbiote has transferred its thoughts and feeling towards this new relationship with Izuku, and he can honestly say that it is almost too good to be true.
"We need each other." Izuku says out loud, he can feel the symbiote squirming in satisfaction, and sinking more permanently into his body. He starts to sob in happiness.
The deal between human and symbiote is quite simple and very mutually beneficial. The symbiote will feed off his bad emotions, such as; anger, angst, anguish, annoyance, anxiety, depression, despair, envy, grief, guilt, hatred (not that he has any), shame, shyness, and worry. It won't take so much that Izuku can't feel his own emotion, but enough so that he can react accordingly. The symbiote has shared its absolute disgust with eating off of happy/good emotions ('too sweet', he says) and has promised that Izuku has plenty of other crippling emotions for the symbiote to choose from. And to sweeten the deal for Izuku, the symbiote is willing to share its powers with its host to do as Izuku see's fit.
"Is this really happening? I'm not just dreaming, right?"
'Nope. Here, I'll help you get started.'
Before Izuku could even comprehend what the symbiote said, his body was taken over by the being inside him. Izuku's body excreted dark green that quickly formed like a second skin around his entire body. He jumped half way up a building without even trying, wall-crawled up the rest of the way to the roof, 'I just stuck to the wall like a bug.' Izuku deadpans, totally shell-shocked. 'No, like a Spider.' He corrects himself. He ran across the roof at speeds he never thought he would achieve, he jumped and threw up his arm and let out the same kind of substance out of his wrist. The rope-like green web-thing, 'I think ill just call them webs', hit a crane and stuck to it before he started swinging.
It was a surreal experience for Izuku, he quirkless, friendless, hopeless just 5 minutes ago. And now he is stuck in his own body, watching through his own eyes and feeling the movements of the symbiote, committing them to muscle memory.
'Okay Izuku. Your back in control, don't freak out! Ill be watching.'
Izuku stumbled in the air for a moment but quickly regained his senses and fired a web to stop his descent. The freedom and feeling of the wind pushing against his face was too good. He let out the scream of pure joy as he preformed mid-air acrobatics that left him giddy with ecstasy.
He felt a strange tingling in the back of his head. It couldn't be explained, but he did what he thought was right and followed it through some alleyways and streets, stopping a few times to find the sensation again. Arriving about 3 blocks away from before, he saw the sludge monster from this morning. The tingling spiked when he laid eyes on what was in his jaws, and he moved before he could even think about it.
He flipped over the crowd and before the monster could react to him, Izuku twisted his body and kicked him in the eye. His foot went right through it. He wasted no time and used both hands to shoot webs towards the hostage. The hostage turns out to be Katsuki Bakugo, Izuku's once childhood friend turned tormentor. Izuku and Katsuki Bakugo shared a mutually shocked glare. "Why are you here!?" He demanded.
"Because… You looked like he needed help. Any my body just moved by its self. I really don't understand why!" They made eye-contact before Izuku yanked him out of the villain's mouth.
They both landed in a heap as they scrambled to get up. Izuku felt his tingle sense, ('Wow. Need to think of a cooler name for that.') much stronger than the other times. It hasn't steered him wrong yet, so he threw himself into Katsuki Bakugo and saved them both from being turned into mush, as the villain absolutely devastated where they were standing not even a second before.
All Might came out of nowhere and held the villain in his clutches. "You have managed to persuade me… that my morals are not just there for me to listen. I must set an example!" He says towards Izuku, not taking his eyes off the villain. "THE PROFESSIONALS ALL PUT THEIR LIVES ON THE LINE, WHEN IN THE GAME!" "DETRIOT… SMASH!" All-Might punches the slime so hard, he creates a tornado. Powerful winds almost knocking over the crowd watching the confrontation.
Even though All-Might basically said he couldn't become a hero (he felt pretty sore about that), seeing his power is still impressive.
Izuku was reprimanded for putting himself in such danger. Even though he saved Kacchan's life. While Kacchan was complemented by the heroes for his impressive and powerful quirk, some even offering him side-kick positions right then and there.
If it weren't for the symbiote feasting on my anger and injustice, I think I would have broken down in front of everyone.
"Hey! Good for nothing!" Izuku heard Katsuki yell out to him. Izuku turns around to face him. "I never asked for you to help me! I didn't need to be saved! Okay! YOU GOT IT!"
'Oh yeah. I could totally tell.' The symbiote quips sarcastically.
"I can take care of myself! I owe you… but there's no way I'm going to apologize to a 'good for nothing' like you!" Katsuki looked absolutely livid and physically strained himself to yell this out before he abruptly spun on his heel and stormed off.
"That was the best 'thank-you' I've ever heard from him." Izuku says with a small smile.
"I'M HERE!" All-Might dashed out of nowhere right in-front of Izuku, scaring the shit out of him and making him jump.
"A-All-Might! What are you doing here?"
He transforms back into a skeleton after coughing up some blood. "Kid, I came to thank you and make some corrections… I thought you didn't have a quirk?" All-Might was confused and a little bit hurt that Izuku didn't tell him of his quirk.
"I only found it right after you said I shouldn't become a hero." All-Might flinches at the accusation but doesn't deny it. He sighs dejectedly.
"I have a proposal for you. If it hadn't been for you, then that kid would have probably died. And I just stood there and watched." He said, disgusted with himself. "You even told me I had fake muscles!" He chuckles to himself. "And for that, I must thank you!"
"Don't… From the beginning, it was entirely my fault. If I hadn't disturbed you during your work… and I was disrespecting you, I didn't even have an 'Individuality'."
"You were the only one who acted. A shy teenage boy who didn't even have their quirk for an hour, rushed in and saved a life, while the pros just waited for someone else. THAT REALLY TOUCHED ME!" "YOU CAN BECOME A HERO!"