Luigi puffed for breath as he raced along the roads of the city Rosalina had brought him to, ignoring the tall buildings that rose so far above his head it made Mushroom Castle look like a hovel. He'd learned a few things since his arrival that he'd dedicated to memory. His host was named Saitama, and was apparently always relatively strapped for cash, a problem Rosalina's proposed payment had neatly solved. Saitama was an Official Hero, whatever that meant. He also knew this was Z City, considered to be one stepped removed from hell itself by everyone who didn't live there, as anyone who actually lived there - save Saitama himself - was of the opinion people had an easier time taking care of themselves in hell.

None of this was really important to Luigi, except for the parts that told him exactly why Rosalina felt him managing to just survive here would leave nothing to truly frighten him in the Mushroom Kingdom. He'd already seen numerous insane things roaming the streets that he'd fled from during his training, only for Saitama to step in and casually reduce the monstrosities to bloody smears, not even seeming to be aware he'd just fought something...or just killed something. The first time Luigi had seen it, he'd evacuated his lunch into the nearest garbage can. The most recent time he'd seen it, his only reaction had been to make sure nothing had gotten on his clothes because gore stink plus training sweat plus sun heat would put him off his dinner.

And he'd only been here a week. He already found himself checking himself over in the mirror, just to be certain it was still him there. The first time, Saitama had said he would get used to it. He hadn't realized how quickly he would.

Then there was the training itself. Running, push ups, sit ups, pull ups...it seemed like very basic training to Luigi, the sort of thing he kept trying to get Mario to do to get to a healthier weight. As fit as the brothers were, Mario tended towards the chubby, and while that was good for jump damage it wasn't good for his heart...or other organs, for that matter.

Luigi didn't question the training to overcome fear itself being such basic training. After all, the sort of things that would leap out of alleyways in the midst of training made it all the more intense on its own, without wondering why the training itself wasn't more intense.

Even as he ran today, though, Luigi kept looking around worriedly. Saitama had said he'd be going shopping while Luigi was training today, which meant he wouldn't necessarily be able to step in to help him if he found himself in danger. He would have to-

"WOOOAAARUUUGHHH!"

Luigi leapt and let out a scream of fear as he heard that noise. Turning around, he saw a creature that was half-flesh, half-machine, and all ugly charging towards him on wheels as a mouth opened wide to reveal gnashing teeth. Luigi desperately raced ahead, trying to escape the creature.

Up above on a nearby building, a blonde cyborg shifted, preparing himself for combat...only for a red glove to grip his shoulder. "Sensei?" he asked in surprise.

"Leave him to it, Genos," Saitama said softly as he watched with his usual bland grin. "He can handle it."

"Are you certain?" Genos asked worriedly. "You've only trained him for a week, and he's only human."

"It's Luigi," Saitama replied readily. "He's been handling things like this for years, and this one's just a small fry. It's only how much more terrifying it looks that's giving him problems. He'll show his stuff soon enough…" His eyes gleamed, showing...interest.

Luigi continued to run, unaware of the discussion above him. He desperately tried to think past his fear. He had to figure out how to make this thing stop moving so he could get away, or do enough damage to make it stand down. But how could he make a half-metal, half-flesh-

Half-metal.

Before he was even consciously aware of what he was doing, he lowered his body to smooth his running plane as he cupped his hands together under his chest. Electrical energy gathered as he focused on the Thunderhand technique. He'd managed to do quite a bit with it, but always with his brother's help. Well, it'sa time I jumped on my own two feet! he thought silently to himself.

Spotting a telephone pole, he saw his chance. Racing forward, he leapt into the air before kicking off the pole halfway up its height. As the monstrosity raced below him, Luigi launched the large sphere of electrical energy he'd gathered down just like when he and Mario used the Thunder Bros technique. The creature roared in pain as it slammed into the pole, causing it to fall towards Luigi to surround him with sparking wires.

Charging the Thunderhand again, Luigi used that to shield him as he grabbed the sparking wires. The electricity running along the wires sent them spinning rapidly around the fallen pole as he let out a terrified scream...releasing at just the right moment to slam feet first into the creature's head at top speed, driving it into the ground.

Luigi leapt free, staggering a bit as he checked the creature over, hoping it would be down for the count. He felt fear surge through him as it slowly got back up, but he desperately held his ground, braced for combat.

The creature took one look at him and raced off in the other direction. Luigi let out a sigh of relief as soon as it was out of sight.

"Not bad."

Luigi let out another scream of terror as he leapt into the air, spinning to find Saitama standing there, grinning widely. "Don'ta do that!" Luigi gasped out as he patted his chest.

"You didn't take it down, but you faced it down and scared it off," Saitama continued. "Not bad at all for your first solo challenge." He then gestured to the metal man beside him. "This is Genos, my other students."

"A pleasure to meet you, Luigi," Genos greeted with a bow. Confused, Luigi bowed back.

"From now on, in addition to your regular training, he'll be your sparring partner," Saitama explained.

"I look forward to testing myself against you," Genos added fervently.

"...Mama Miia…" Luigi groaned, slumping back onto the ground.

"You still have another third of a mile to run," Saitama pointed out.

"Right!" Luigi confirmed as he leapt back to his feet and got back to running.

Black. Purple. Unnatural Blue. Unhealthy white.

These were the colors that swirled together in the pool of negative energy, like an inverted photograph melted off its frame. The energy focused in the pool writhed and swirled, struggling to take shape...but there wasn't enough substance left in the pool for the many shattered soul fragments within to form anymore. All that was left was rage, pain, sorrow...and vengeful desire. Each soul fragment was focused on a single being as the focus of its fury, that single focus binding the fragments together as they struggled to form.

A figure in shadows stared at the pool as it sat in a capsule. "So...what is it, exactly?" he asked as he stroked his chin.

"A wellspring of dark power, hatred, and soul fragments," another, higher pitched voice responded. "None of the fragments are from the same soul...and they seem focused on a single individual."

"Hmm...put some magic in it," the first voice, much deeper and more powerful, instructed. A deep guffaw echoed in the shadows. "It'll be fun to experiment-"

Fun

"Just a guy...hero for fun…"

The wellspring writhed and thrashed, shaking the capsule and struggling to break free to unleash its rage, sending the capsule bouncing off its braced location to fall towards the ground.

A massive orange clawed hand caught the capsule before it could break. "Well, aren't you angry," the voice murmured wickedly. "Well, we'll see what use that anger can go to…" Flames briefly illuminated the shadows, and glowing eyes stared down at the capsule...containing an unquiet mass grave.