The Villager in Smash Bros (aka, my funny little guy since 2014) is a composite of multiple different games - while the shopkeepers and recurring NPCs change from title to title, there's nothing to suggest that the player character changes or is the same at all. Obviously as an avatar they're limited in how much input they can give...
But his design is directly taken from City Folk and Wild World, yet he's given the New Leaf "Mayor" title? He's said to help out with the Pocket Camp and makes consistent appearances in New Horizons promos? Bits and pieces from both Smash and AC make him feel distinct from other player designs and a pure avatar position in general.
SO! Here's an official updated masterpost of how I see the guy from game to game and my headcanons/interpretations of his character (+a bit about the alts too)
Tobey World (scrambling Murabito -> Tobey and also because it feels fitting), more commonly known as Villager, specifically represents the Wild World and New Leaf entries of the series. The intro questionnaire answers needed to get his look are a lot more energetic (if slightly uncertain) in the earlier games, but lose that to a more straightforward set for New Leaf. In terms of AC personality types, I read that as a natively lazy personality that, after the events of WW, shifts to cranky going into NL. For contrast I’ve also included the answers of Chelsea Folk - the default female villager representing City Folk in this case. Her answers tend to be similar but a bit more confident, even spunky! The two know each other well since they show up often in official graphics together.
Villager tends to brush off some insecurity in himself with an insistence on staying on top of things, keeping them under control as a reliable mayor/fighter. He often acts uninterested or (loudly) annoyed when things don’t go his way... This causes him to butt heads with some other strong personalities in Smash. At heart he’s still a kid though, and that excitement comes out whenever 1. he takes care of his town or 2. he gets to participate in SSB!! AC characters naturally emote when their feelings are strong enough, but to use them on command you have to learn them from others, so he can't actually manage them that well. Villy has a knack for catching things, a love for gardening, and while not as much as, say, Pit, a demonstrated interest in Nintendo games which contributes to his readiness in joining the fight.
Now for a possible timeline... what made him shift his attitude between games? Well with those first couple iterations:
Early: Born the only child in the only human family of his Wild World town, Tobey grew up in an environment of animosity - often a target of bullying and harassment by the ruder/more hostile neighbors of the era. His parents tried their best, but outside of them the closest thing to a friend was a pink-haired girl from the next town over. He’d only ever see Chelsea on occasional family trips to the city, passing through the Checkpoint Gate between their towns.
New Leaf: When Tom Nook takes off to a new town, Tobey’s family sends him to follow their employer. On the train there a mysterious cat approaches him and they chat a while, Tobey rather unenthusedly. He steps off to find out that he’s been mistaken for the new mayor - the promised “only one off that train”. As a result, he is welcomed by the townsfolk with open arms and jumps into work. Becoming mayor is the best thing that could have happened; he clings to it like a lifeline.
SSB4: Back in the Brawl days, the previous mayor, Tortimer, offered a chunk of the town for use in the Smash tournament and renamed it to “Smashville”. Out of honor, Master Hand goes right for the town when it comes time for a new AC rep. Tobey knows of the multiversal fame in the Smash Bros name and rushes in to join. There, he reunites with Chelsea for the first time since his move, works his way into a group of newcomers and other kids his age, and takes on the “Villager” role eagerly.
Between SSB4 and SSBU: Diligently continues his mayorly duties and helps to set up the nearby Pocket Camp, before turning it over to some of the other villagers he’s met through the tournament.
SSBU: He comes back less rough around the edges, helping him settle some friendships (but not all) more cleanly. Isabelle’s arrival also helps immensely as he tries his best to help her adjust. Despite the threatening newcomers, he doesn’t have much to worry about personally, until…
World of Light: There’s no resisting when Galeem destroys everything, and he can’t help but panic. Villager is one of the three options to save right at the start, so the guilt of being saved by Kirby and Mario first (and leaving behind the Sheik+Marth) eats at him throughout the campaign. Gradually they loop back to them as well as rescuing his other friends until the whole group can stand together at the final battle.
New Horizons: To thank them for their assistance in shutting down the World of Light, and as a much-needed break in its aftermath, Tobey and Chelsea are invited to the Island of New Horizons for free. Isabelle officially steps down as Smashville secretary to begin work on the island. Villager, for his part, crashes every time he goes.
His more significant relationships within the Smash cast are with most of the other preteen fighters like Toon Link, Ness and Lucas (I am not immune to the "Smash Kids" friend group) and SSB4 newcomers. Relationship chart headcanons below!! Some other AC NPCs that should have been included didn't have any icons, but as a whole he's neutral-to-friends with most of the New Leaf NPCs. Notable exceptions include Redd, Resetti and Rover
As for the other alt/promo villagers, the rough breakdown imo would be:
Villager/Murabito/Tobey (red) = Wild World+base New Leaf (most like the cranky personality type; probably was lazy before but shifted over time)
Aldeana/Chelsea (pink) = City Folk (most like the snooty personality type)
Yellow boy = Population Growing (jock), since his starter shirt+face are only available in AC1
Green turnip girl = Nearby AAAAAA town in place of Isabelle (normal)
Lime girl = Happy Home Designer (uchi/sisterly)
Blue stripe siblings = Amiibo Festival (lazy boy, peppy girl)
Purple boy = Pocket Camp + Complete (smug)
The MK8 Villagers also represent New Leaf, but specifically the Welcome Amiibo version… Maybe they take over the NL Nook’s Cranny once Tom Nook moves to New Horizons
New Horizons + Happy Home Festival specifically treat the Smash Villagers as cameos, so I just use the promo villagers instead - most likely the orange haired trailer girl
Oh also I like to give him the Special Edition ACNL 3DS to both play games on and act as a virtual check-in window for his town. It's never far away!
