Levi stood in the kitchen of the Mercs new house, rummaging around in the fridge for ingredients.
They'd bought the house not too long ago, with some cash they'd got from tasks.

His room, one of four, was pretty simple. A bed, a nightstand and decent sized closet.
Even though they'd been there for a few days time, he had yet to personalize it fully. But he had put up some posters and such, leaving his kunai on the nightstand.

Finding what he wanted, Levi pulled out the stuff he wanted and set it on the counter. He scowered the cupboards for the whole wheat and set the bread on a plate. Adding mayo, ham, lettuce and tomatoes.

Walking out onto the balcony with his meal, he gave a nod to Catena, who was sitting in the shade...

Quote from Ignusburns

Levi stood in the kitchen of the Mercs new house, rummaging around in the fridge for ingredients.
They'd bought the house not too long ago, with some cash they'd got from tasks.

His room, one of four, was pretty simple. A bed, a nightstand and decent sized closet.
Even though they'd been there for a few days time, he had yet to personalize it fully. But he had put up some posters and such, leaving his kunai on the nightstand.

Finding what he wanted, Levi pulled out the stuff he wanted and set it on the counter. He scowered the cupboards for the whole wheat and set the bread on a plate. Adding mayo, ham, lettuce and tomatoes.

Walking out onto the balcony with his meal, he gave a nod to Catena, who was sitting in the shade...

This story seems a bit bland. I'm fine with being simplistic, but this seems to be lacking some salt.
First Bold: Scowered was a good adjective(even though the correct form was scour), but then it falls flat at the condiments list.
"Adding mayo, ham, lettuce and tomatoes." Woo hoo. Maybe it can go like this:
"He piled on creamy mayo, somewhat-chunky ham, crisp lettuce, and bold red tomatoes, and slapped another piece of whole wheat on top."
Second Bold: People don't give just a nod. They can give a rude, punk-ish nod, a curt nod, a casual nod.
Get the picture here? Even though it is a short story, you still need to make the reader be able to picture everything, even something as simple as a sandwich.

Levi vs Catena: Spar

Levi needs training. After that huge score on… uh… whatever. Just make sure he knows what he’s doing. Those were the orders that were given to Catena. She took off her sunglasses, and threw them on her bed. With a small flick of her wrist, the chains that wrapped up her door unlocked.
“Can’t believe I’m resorted to locking up my door to keep those boys from bothering me. Gosh.”
Catena walked out of her room, turned towards the corridor, and knocked on Levi’s door. “It’s Catena.”
A loud thud came out from the room, and the door swung open, revealing a blonde teen with is back against the wall. “Hey Catena. How’s the food treating you?”
Levi smiled, and threw some gum in his mouth. Catena just stared at him. Levi stared back. After a minute, he finally dropped his smile and stopped leaning on the wall. “Ok, you’re scaring me. What’s up?” Levi asked.
Catena shrugged and said, “just messing with you. It’s training time.”
The duo walked to the backyard, greeted by a grinning Kiro, nodding to the music in his headphones.
“Let’s go.”
---
The team arrived in an empty garage of an abandoned mall, filled with broken street signs, graffiti, and a couple manikins posed in sexual positions.
“You did well choosing this location,” Catena smirked. Kiro simply shrugged, turned towards the others, and stomped his right foot upon a tin can.
“Alright-y, how are we going to do this? Walk 20 paces away from each other and then just go? Or what?” Levi asked, a thin trail of smoke coiling around his right hand.
Catena stepped back a few steps, and said, “May as well start now. Dodge.” A bottle flew towards Levi at high speeds, which smacked him in the face.
“Ow.”
Levi then flung his kunai at Catena, and started to sprint towards her. A small link of chain shot out of the ground and deflected the kunai, which Levi caught in his hand.
“Oh man, this is going to be great.” Kiro murmured.
Levi thrusted his kunai at Catena, who side-stepped and dodged it. At the same time, her knee came up and made contact with Levi’s stomach. But just as she was about to send her fist down at him, he dissipated and reappeared behind her. With one swift kick, Levi sent Catena tumbling towards a pole.
“Okay, I deserved that one.” Catena whispered, while surrounding most of her body with chainmail.
“Oh man, that looks sick. Lemmie try” Levi said, mirroring Catena with his smoke. He then proceeded to collect all of the smoke towards Catena in a large cloud. Catena began to turn and run right when Levi appeared before her and swung his fist towards her. The loud thud of metal on bone rung loudly around the garage. Levi staggered backwards, surrounded his broken fist with smoke, and drew his kunai. Catena began to summon chains from the ground, forming a steel gauntlet around both arms. Levi raised his arms, and started bouncing on his toes. With two swift steps, he did a roundhouse kick towards Catena’s face. Catena dodged his foot, but Levi used his momentum to swing his kunai towards Catena. A small drop of blood fell to the floor. Catena wiped the blood off her face, and a large column of chains rammed Levi in the side.
“Always watch your surroundings, kiddo.” Kiro proclaimed, and offered his hand to the dazed Levi on the floor. Kiro pulled Levi up, and then said to Catena, “you didn’t have to ram him that hard.” Catena gave him her best smile, along with a cheesy peace sign. The ‘sorry-not-sorry’ was heavily apparent.