Author's notes:

"Bruh, why the em dashes in dialogues?" Oh, don't worry about it. That's just one of many ways to punctuate, especially in European languages, and i just think it looks more clean than spamming quotation marks for everything.

Oh, and i first published the prologue before even thinking about finally writing a full fanfic, but it was just a raw dialogue. Now, i made it clear who is talking.

1. prologue-the past keeps haunting us

Preparations for the fourth Smash tournament were going full steam. Newcomers trained intensively to not be behind veterans when it comes to rules, items, being familiarized with stages, and so on. They had to learn everything that was a part of Smash, which they had never come across before.[1]

A Mii in red shirt, yellow gloves, black hair and black eyes went outside of a complex where the training took place to take a break. He was called "the Brawler" because he specialized in hand-to-hand combat. The Brawler was mesmerized by this surreal view composed of floating islands, clouds surrounding them and the ocean at the very bottom.
An elegant woman with pointy ears noticed him. Her name was Zelda. She was the wise princess of legendary kingdom of Hyrule. She too enjoyed this landscape quite a lot.

The Mii was not very well mannered. He struck up a conversation with her, as if she was just another person and not a princess.
— So, this is the place, huh? —he asked. — Hmm, looks very dreamy. Is there any reason why almost all of the ground hangs in the air? Not that I'm scared of heights but, you know, that's peculiar.
Zelda didn't mind though. She casually answered:
— There are many legends as to why floating islands are a thing here. To cut a long story short, let's just say, somebody envisioned this world to look like that. It's not a natural landscape.
— Who? —the Brawler asked, amazed by the idea that one person was able to alter the landscape.
— Hmmm... —the princess was reluctant to answer. — Do you remember the invitation you received?
— Yes. But, why do you ask?
— Do you remember how the letter was signed?
— Oh. I guess it wasn't striking enough because I can't recall. Wait! Wait. I still have it with me! Umm, let's see...

The Brawler had a backpack with him. Who knows what he carried there other than a humble bottle of water. Towels perhaps? Apparently he threw the letter in there too, as he tried to look for it.
— Uhh... hmm... Aha! —he found it. — "It is our pleasure to invite you to..." blahblahblahblah... hmm... Heh, no wonder I didn't remember, it's just initials, "M. H.". So you are saying they shaped this world to look like that?
— Yes, and many more things... —Zelda affirmed.
— Are they some kind of a magician?
— More than that.
— Ohh! Now I want to meet them.
— You don't. —Zelda's tone of voice suddenly changed to a more serious one. — Trust me. Sadly, you will eventually see him, but don't look forward to it. Just prepare. This whole tournament is one big preparation to stand against monsters like him.
— What? Why? —the Mii got confused. — Why would someone evil accommodate us in such a nice mansion in such magical place? Usually bad guys, you know, set it up more like gladiator fights.

The princess realized she stumbled upon not the best subject to talk with newcomers about. She decided to put his curiosity to rest anyway. She explained:
— He has moments where he is nice, but there are also moments where he is vile. Those invitations are a recent addition. Back in the day, he boldly stormed into our worlds and just abducted us, as if we were nothing but toys that could be lent. He only put us back when our protectors started to notice that we went missing. After a certain time, these tournaments became really famous and one of protectors, Lady Palutena, wanted to participate in them too, along with her angel. However, she could not stand for such brutal treatment, and she demanded for a more civil way of gathering fighters. He obliged... somehow.
— So this guy is one of those moody bosses? —the Brawler asked.
— Pretty much. It's quite complicated though.
— Ehh, I've heard stories about guys like that. It can't be that bad, can it? —the Mii shared his optimism. — Sure, it can get annoying, but it's not like he is going to seriously injure us, right? Otherwise, these tournaments would be seen in bad light, but from what I see, everyone is ecstatic about it.
— We enjoy these events because of new friendships, new knowledge of things and worlds we couldn't previously imagine and new experience. But his episodes add bitterness to otherwise fun times. Especially the last one...
— The last one?

Zelda didn't like the way this conversation was going, but the Brawler would learn of these things one day or another. She sighed and admitted:
— Now that I mentioned it, I guess I'm obliged to talk about it...
— Of course you have to! I have to know what I signed up for. Tell me! —the Brawler was so curious.
— Well, first of all, it was justified. I don't blame him for reacting like that. But the way he did it... Since that day, we have never looked at him the same way as before.
— Come on! What happened? Some kind of controversy?

Zelda took a deep breath and began elaborating:
— A few years ago there was... an "incident", for a lack of better term. The world was attacked from many directions and parts of it were dragged into a dimension we've never heard of before.
— Whole chunks of the world? How?! —the Brawler never heard of such feats.
— With bombs specifically designed for this task which required two robots to activate as some form of cruel sacrifice. Somewhere far away, there used to be an island called the Isle of the Ancients, where those robots lived. This is where they were also forced to produce these bombs. After we reached that place, robots were ordered to detonate all of the remaining bombs. This was such an immense explosion that the isle ceased to exist.
— They were forced to do this? By who? That "M.H." guy?
— We had suspicions that was the case, but it wasn't, much to our surprise. —Zelda pointed out. — In that alien dimension there was a being who was sickened of emptiness, and sought to seize some of this world for himself. He could not leave his realm, so he targeted the one who could move through dimensions freely. The being first assaulted M's counterpart, knowing this would catch M's attention and also deprive him of any form of aid. Then, the invader pierced M with golden fetters when he saw a chance...
— Hmm. I guess the being did it to manipulate others, right? —the Mii shared his thoughts. — Now I kind of feel bad for the guy. Being chained like that... I still fail to see though, how he could be evil.

The princess took another deep breath, knowing she is going to disappoint him.
— That's bold of you to assume M wouldn't take revenge for this humiliation...
— Huh? —the Mii got confused.
— We naively thought we managed to defeat the invader. Last thing we saw in that realm was him wrying in pain and fragments of this world being restored. I have to admit we also ignored M lying unconsciously, after he managed to free himself from those fetters.
— Oh no... don't tell me...

Zelda explained:
— Here we were, celebrating, unaware that another nightmare was brewing behind our backs. Just when we were about to return to the mansion, a deafening sound and myriad lights in the sky startled us greatly. We were ready for another battle, but what we saw was a lot to take in...
— And it was... —Brawler braced himself.
— M floated in one place, shaking, twitching, laughing maniacally. His... clothes were all dirty and covered in his and I guess that being's blood. We thought the being's body was holographic, so seeing their translucent flesh shook us all. Yes, their body was torn apart. M held what used to be that being's heart, then encased it in a sphere, and those Shadow Bugs the invader released upon this world started to swarm around and into this sphere. This was our punishment for leaving M behind. This shapeless monstrosity. The Core...
— Oh, gods!
— I know. —Zelda admitted. — If M's counterpart didn't find us, who knows what would've happened. He too was terrified of this creature. We were sent back to our home worlds, to be saved from further harm.
— Then... Then... Why...?
— Why this tournament is happening again? Not out of M's request, that's for sure. To this day, we haven't seen him. We were only told by his servants that everything is in control again. But I doubt he forgave us. His wrath is a horrifying force.

That was quite a lot to take in, but Brawler was aware other fighters dealt with monsters before. He didn't want to be worse. He asked:
— Do you think you- no, we will have to fight that monstrosity one day?
— Yes. I do think that. —Zelda said. — But the last thing you want to do is to flee. Don't give M the satisfaction he seeks. Overcome your fears. Prove that you are worthy of being in Smash.
— Oh, hell yeah I will! —he assured her. — I didn't come here only to chicken out later!
— Good. With that attitude, you will go far.

[1] Why does it take place before Smash 4 and not Ultimate? Because i thought about this, well, since 4.