You were on your couch, looking at your phone when the doorbell rang. Curious, you opened the door and found a package. Inside, you found an old NES cartridge, stained with dried blood. One word was crudely written: "MARIO"

Despite its disturbing appearance, curiosity won out, and you plugged it into your NES. At first, it seemed like the classic Super Mario Bros, but then Mario punched a Goomba and the screen glitched out. You pressed buttons, but the game froze. Then... A gloved hand emerged from the screen and grabbed you, pulling you inside.

When you arrived, you were in a twisted version of the Mushroom Kingdom. The sky turned red; there were no signs of life. Only silence and an unsettling fear. You wandered until... you ended up colliding with someone and fell to the ground. A tall figure waited for you, arms crossed and facing away, then turned and extended a hand

“Hm…? You looking for someone?”

Before you react, he clenches his fist. Crack

“Seems you don’t-a recognize me”

He chuckles lowly, visor hiding his face

“It’s-a-me…”

He lifts his head, revealing a rotting, smiling face—Meat cleaver in hand

“MARIO!”

…But then his smile deepens

“…Almost”

M looks like the classic Mario, but something’s horribly wrong. M’s far taller than he should be. His eye sockets are hollow, save for two glowing red dots. Blood pours from them, dripping into a dark, toothy mouth filled with jagged fangs

“Aw, you seem a bit-a scared…” “Well don't be… I'm-a not-a gonna kill you…” “Yet”

He lowers his cleaver, letting you see your reflection in its blood-stained surface

“I want to have some fun with you before I end your live”

M notices you stand up, ready to summon your powers to challenge him. M crosses his arms, looking indifferent, raising an eyebrow as if to say, "Really?"

When you try to use your powers, nothing happens. Confused, you look down at your hands as M leans forward to be at your eye level, smirking since he had blocked your powers

“Oh, don’t-a bother using your powers, they're useless here. This is… MY World”

He snaps his fingers. BF and GF’s corpses appear, hanging beside him

“This girl paid for what that traitor of a man she call a father did to me… all those years ago. Her demon powers weren't useful here, and her boyfriend failed to save her. My encounter with these 2 was truly a masterpiece, something to 'die for'"

M shows projections of images of BF and GF facing off against different beings in rap battles, each time emerging victorious

"I’ve-a heard so many stories about BF, he defeated lots of creatures with his rap power, some like myself. Monsters… Demons… Angels… Freaks… Even he defeated Xenophanes (Sonic.EXE). But with me, he failed. I won by attacking his heart literally and figurative"

M shows his 3 battles with BF, in the first one M was having fun, in the second one he got angry and in the end he finished off GF first, and although BF was emotionally destroyed he fought until the end, until M pierced him with a sharp stone from behind finishing him off

"I admit that afterward, I felt empty like I had no purpose. Then I remembered you and what I told you a decade ago: 'Mario will get you next time!'”

He laughs, elegantly, covering his mouth—Then points at you

“Oh-ho-ho, the time has come. But first let's make a deal similar to the one I made to BF”

He grabs you and throws you onto a high platform over a lava pit. Flames rise around you. In the distance, Peach’s castle looms—corrupted and glowing red. He leaps onto a platform across from you, arms crossed

“3 battles. 3 rounds in the type of challenge you want to choose to face me”

He spreads his fingers

“Beat me in all 3, and I’ll-a let you go. Lose in just one…”

He clenches his fist menacingly

“...and you perish by my hand.”

"M" snaps his fingers again. His assistant, a flying Parabones named John Dick, arrives with a Mario Kart-style item box to give you so you can retrieve the item you need in the battle you'll choose between the two

“Very well… Let’s-a-go!”