I'll be honest, most of these choices could swap places and there wouldn't be too much of a difference, but when i was making this top 10, Simon Belmont was already number 1, and i wouldn't have it any other way.
I love the Castlevania series, from it's humble begginings on the NES to the more animesque Metroidvanias on the DS, it's a franchise rich of lore, gameplay and music, with a very interesing cast of characters from the bishonen dark prince Alucard to the underapreciated agile pirate Grant Danasty to the adorable Maria Renard, but none of them are as important as Simon Belmont, the most renowed of Vampire Hunters, the most well known member of the Belmont Clan and one of Konami's most prominent mascots, appearing as the main Castlevania representative. Castlevania is a series that is prominent in gaming, is heavily remembered by fans of retro-gaming and most gamers that lived in the late 80's to late 90's.
His moveset is so damn easy to figure out, and the fact that he comes from a series of side-scrollers makes him much easier to implement in Smash's Platfrom Fighter gameplay. He could be a slow and heavy but powerful character that instead of relying on close ranged melee attacks, he instead will use the long-ranged weapon, the "Vampire Killer" which can be used diagonally (diagonal aerials and Smash-attacks everyone?) and can be engulfed in flames and even shoot fireballs. There's also his repertoire that includes daggers, cross-shaped Boomerangs, Holy Water that burn the enemies in place and sometimes travel a certain distance, axes he can throw in an arc, a time watch that allows him to slow or even outright stop time, etc.
The reason as to why i want is also the reason why i want Waluigi: Attachment to the character (and also the franchise).
Originally i just saw him as better "Konami Rep" than Snake, but as i grew older, i realized that was a stupid reason to desire a character (especially a guest character) and i also realized Snake was not that unfitting.
I grew a bigger connection to the Castlevania from my late Childhood-puberty years, and i loved almost every game that i played in the series, but none as much as Super Castlevania 4. I loved that game so much, i bought the SNES Classic specifically for that, alongside Kirby Super Star, A Link to the Past, Super Punch Out, DKC and Super Mario RPG.
Third Parties are at the end of the day, Guest characters. For me, adding any Third Party willy-nilly will damage the appeal and make it not as enjoyable. For me, a Guest has to be important, renowed and special, an icon of an era or the face of a longrunner series. I know that Simon is not on the same level as Sonic or Pac-Man, but for me, and many others, Castlevania is important, The series has sold 20 Million Copies, and while that is not so big compared to the sales of other franchises (like Dragon Quest or Kingdom Hearts or even Imagine for some ****ing reason) it's nothing to scoff at either. Not only that, for me, Simon Belmont is practically a Nintendo Character that unfortunately does not belong to Nintendo,, his game was released in the same year as important Nintendo franchises like Zelda and Metroid, and the series has been heavily assosiated with the Nintendo Consoles of old. He may not be as iconic as say Cloud, but he is to Castlevania to what Cloud is to Final Fantasy, the most renowed protagonist of the series that is capable of representing the franchise on his own completely.
I know my arguments may seem fallocious (and they probable are) and that Simon Belmont is not that requested, and i know that. I know the reality of the situation, im not expecting him to be in the game, and i feel that we will be lucky if we even get Snake back.
Simon Belmont in Smash is not a prediction, is not a guess, hell it's barely a request because i know it would be asking for the moon. Simon Belmont in Smash is a dream, a dream that will always be in head and in my heart.
.........i just hope the Netflix series doesn't **** up his portrayal (looking at you Judgement)