Disclaimer
One Punch Man is a webmanga by One, and is also a published manga redraw by Yusuke Murata (Eyeshield 21).
It contains lots and lots of heroes, and has a simplistic apathetic classic hero as its main character. Track it down if you can; it's ridiculously absurd, but really good too.
wkz most certainly does not own it.

Worm is a completed web-serialization by Wildbow.
It contains lots and lots of villains, and has a complex proactive atypical villain as its main character. Track it down if you can; it's ridiculously lengthy, but really good too.
wkz most certainly does not own it either.

Meh, I can take them all! is an ongoing fanfic crossover by wkz, who shamelessly stole material from both of the above.
No prior knowledge of both sources are needed, but as with all fanfics knowledge of the origin material will increase your enjoyment as well as inoculate you against spoilers from both series. Enjoy.

Arc 1: *Training Montage*
Snip #1

I knocked on the door. There was a muffled reply from the other side, and I entered as instructed. We laid eyes on each other during the small moments needed to close the door, the Director of the PRT in the middle of her lair and me, a jobless common branch office sales manager. We were about as hilariously mismatched in terms of power, status, responsibilities and power as it was humanely possible to do so without me being a lot younger, or bringing actual powers into the picture.

She waved her hand at one of the available seats, and I accepted the offer.

"Mr… Simon. I'm Director Piggot," she said, her sharp piercing eyes following my every move. Maybe she was sizing me up, I thought as I got comfortable. Maybe she needed to, as part of her job. One eye focused on me, taking in everything and evaluating my capabilities. The other facing inwards, taking in the situation, evaluating the possibilities. And between them, a brain on overdrive, running through a thousand plans, stratagems, and decisions a minute.

I most certainly wasn't. I wasn't even trying.

It was rude, but I still can't get over how FAT she was.

I am ashamed. But the thought had stuck, like barnacles, and refused to go away. I spoke first, more to scrape the metaphorical ship's hull of its unwanted guests rather than any wish to speak first. "So, why am I here?"

Disbelief clouded her features for a moment before she hid it expertly. "I'll be blunt," she said, "You're most likely a cape."

I was still scraping the hull when the dynamite that was her words hit me, the barnacles, the ship and the docks it was in, and blew the whole metaphorical thing to pieces. "I'm a cape?" I managed to stutter.

"You're most likely a cape."

"I'm most… ah. You don't know for sure."

"Not fully, but we're sure enough to have this meeting. How much do you know about powered individuals in general?"

"Absolutely nothing, ma'am. Other than the fact there's an awful lot of fighting in the world today."

"The shortest of summaries then. There is a lot of speculation on the subject, but it is generally agreed that to get powers, you have to a few conditions. One of them is the trigger event."

"I've heard of trigger events, at least." I interrupted.

I think she did not like that. "Explain."

"Huh?"

"Explain what you know, so we're on the same page."

"Oh. Erm… Bad things happened to someone, and they get powers from it."

She continued her icy stare at me as I paused.

"That's about it."

She sighed, and picked up the slack, "That's not all of it, but it'll suffice for now."

"And you believe I had a trigger event, Just now."

"And we know you had a trigger event."

"How?"

"Because we were there, 'just now'. We have people who recognize the symptoms…"

Two hours earlier, I, Simon Tama was a dejected pile of rejected material.

The interview had not gone well.

My car did not start.

A dog pissed on me as I waited to cross the road.

I realized my wallet was in the car, and got screamed at by the bus driver for wasting his time.

My car, with all four of its wheels missing, was merrily burning to the ground by the time I walked back.

And as I stared at the explosion which used to be my car, I saw screaming pedestrians run past me, TOWARDS the exploding car.

I turned around. I looked upwards. And higher up. And I took a step back so I can look up a bit more.

A slug-like face with no nose, protruding eyes and a slit with too much teeth looked right back at me.

Well, fuck me.

We looked at each other for a long time, me and him. I think I got dripped on, his skin apparently producing slime and who knows what. His eyes waved around almost hypnotically, sometimes looking around, but mostly on me.

"Why aren't you running?" he rumbled more than spoke. "All of them did."

I did not reply.

The slit that made up his mouth twisted into a parody of a smile. "Nothing worth living for, eh?"

I suppressed the urge to reply.

"Seen a kid with a salt shaker around these parts?" The surprise must have shown on my face as he shifted his weight.

"No," I answered. Couldn't hurt to answer that question, however out of the left field that was.

"Well. So, I think you and I, we're very similar people." He walked past, patting me on the right shoulder and in the process depositing a lot of slime all over my upper arm, "I think I'll let you live, because of that."

I let out a breath I did not know I was holding.

"Except, you know," the voice was distant and soft, but audible enough, "I have powers. And you still suck. Suffer on, like I used to. Ho ho ho ho ho…"

Well, fuck me a lot.

"When you put it that way, it is possibly the worst moment of my life." I conceded.

The Director of the PRT continued in her quest to lower the room temperature of her room through her stare.

"But here's the thing. I did not have a trigger event or whatever it is called, because I. Don't. Have. Powers."

"Bull. Shit."

And now she was parroting my slow, deliberate, capitalized spoken emphasis.

"I really don't have…"

"Bullshit. You took down a Brute 5 all by yourself. And you say you don't have powers?"

"I had help."

"You have a kid skipping his third day of High School."

"I had bags and bags of salt courtesy of that kid's helpful directions and my tie as a makeshift slingshot. Against a naked guy who's powers are basically 'I'm a slug'. Which reminds me, the only reason why I'm here is because I'm broke. One of your people told me earlier that the PRT will foot the bill I owe that convenience store, so would you?"

She must think she have frost powers, the way she was staring at me.

"Look, Madam Pig… Got, is it? I really don't have powers. I don't think I gained powers, and I really still feel like I don't have powers here."

We continued to look at each other, the silence broken by the dripping of the thick, tough, congealed slime from earlier finally melting off and dropping in clumps from my shirt, my limbs, my body, my… everywhere.

"We will pay for the damages you incurred," the pig finally conceded, leaning back, "out of the reward for his capture. Now get out."

"Thank you very much for your time." I stood up, "I'll show myself out."

An hour of excessive paperwork, sitting through an officer's laments of ruined paperwork due to dripped slime, buying clothing from the gift ship (Armsmaster decal underwear, really?), borrowing a shower, and another hour of paperwork later, I walked out of the PRT building.

I had an ordeal and a hundred dollars out of a wasted days' worth of too much excitement… I really used up a lot of salt back then.

But I digress.

I had bruises all over, a grateful kid's thanks in the form of his pocket change, and my only set of somewhat expensive business attire ruined, in exchange for a day of bodily danger.

But above all, I also had an epiphany.

Capes aren't invulnerable.

It is possible to do good against them, even without powers.

And I think I have a new goal in life... nah, maybe a new hobby in life. Fighting against capes doesn't pay much, the evidence in the mere hundred or so dollars in my pocket.

All I need is some exercise, my muscles reminded me as they ached all over. Got to change that.