I'd like to see them in Smash too! Here's my moveset for them.
"Why not just make them costumes of the Inklings?"
The Inklings in Smash only represent the weapon types and specials seen in Splatoon 1. In Splatoon 2, several new weapon types & abilities were introduced - more than enough source material to create an entirely new fighter to represent the Splatoon franchise.
Due to time constraints, Splatoon 2 doesn't really have much of a presence in Smash Ultimate barring a few songs and a couple of spirits. But the series is incredibly popular in Japan and has a huge fanbase in the West, too. It's the 6th best selling Switch game of all time (Selling 9.02 million units!), right behind Breath of the Wild and Pokémon: Let's Go. In my opinion, this vast popularity should net the series stronger representation.
"Who are the Octolings?"
In contrast to the pampered lifestyle of the Inklings, the Octolings were once brainwashed fighters in the Octarian military. But when they heard the Calamari Inkantation, it nullified the brainwashing effect, freeing their souls. Most (but not all) of them escaped to Inkling society in Inkopolis afterwards, hoping to start anew.
The Octolings pictured above are 'Agent 8' (with two possible gender choices). After being freed from the Octarian military by the Calamari Inkantation, he/she met & fought the protagonist of Splatoon 1 (The yellow Inkling skin in Smash). However, an unknown force attacked both of them and they were knocked into the Deepsea Metro. Losing their memories in the process, Agent 8 proceeded to embark on a journey for freedom once again.
Generally, the Octolings are far smarter than the Inklings - evidenced by their technological superiority in their weaponry & stages, but the Inklings are biologically stronger.
Moveset potential of the Octolings:
With all of the new weapon & special additions in Splatoon 2, the Octolings have some of the largest moveset potential of any newcomer - here are the weapons Nintendo could choose from.
Dualies:
Dualies are a set of pistols that allow the user to perform a dodge roll, allowing for both offensive and defensive maneuvers. The roll does not provide them with invincibility in-game, but it has an extremely short cooldown period and it doesn't get weaker over time. If these were implemented in the Octoling's moveset, they would most likely have a shorter roll that doesn't stale, in addition to shooting like the Inkling's splattershot.
Brellas:
Brellas function like shotguns, but with a deployable shield. Holding the fire button will open the umbrella in front of the wielder, protecting them from all attacks in the direction they're facing. If the player continues to hold the fire button, the umbrella separates from the weapon and flies forward - becoming a moving shield for the wielder (which also deals a small amount of damage to an enemy upon contact). It takes a brief period of time for the umbrella to regenerate, but the player isn't left defenseless - they can continue to fire the shotgun whilst they wait for the umbrella to come back. I believe this would function similarly in Smash, but with the shotgun blast dealing a fair amount of knockback (Like an Ivysaur forward tilt) with a relatively short range.
Chargers:
Though Chargers are present in Splatoon 1, they still have no presence in Smash - which is why I think the Splatoon 2 exclusive Goo Tuber, could be used to represent this weapon type. It would add an interesting dynamic never seen in Smash before (being sniper rifles) and would allow for several creative plays. Unlike most sniper rifles/chargers in Splatoon, the Goo Tuber can hold its' full "snipe" charge for 5 seconds. It takes a while to charge and consumes a lot of ink. This would function almost identically in Smash, with a full charge possibly consuming over half an ink tank but dealing great knockback with a colossal range.
Curling Bombs:
The Curling Bombs, being an alternative to the Splat Bombs in Splatoon 2, would travel in a straight line across the floor when deployed - leaving a trail of ink and bouncing off any obstacle it encounters. The more the bomb is charged, the
shorter the travel distance of the curling bomb. In Smash, I believe this would function identically in Smash.[/SPOILER]
Autobombs:
The Curling Bombs, being another alternative to the Splat Bombs in Splatoon 2, would seek out enemy players once thrown, and move towards them for a long time. Once it reaches a player, or travels far enough without reaching the player, it explodes. If it's thrown and no enemies are in its' range, it explodes just like a splat bomb. In Smash, I believe that this bomb would function similarly - though unlike Bowser Jr.'s down special, you would be unable to pick up the bomb once it's deployed and you would sustain self-damage form it. To compensate, it could be a devastating kill move.
These next few weapons are 'specials' in Splatoon - charged by dealing damage and spreading ink across the stage. When you die in Splatoon, your special charge is cut considerably. I believe that a special meter could be added into the Octoling's moveset, giving them access to these moves:
Tenta Missiles:
In Splatoon 2, these lock onto five opponents using a very large reticle and fire a certain amount of missiles per opponent locked onto. The more opponents locked onto, the less missiles sent to each target - and the enemy has a fair amount of time to react to them. However, they're still deadly and can kill instantly in Splatoon 2 if you don't react in time. In Smash, these would most likely deal a large amount of damage/knockback if successful, but landing the shots would be the main challenge.
Splashdown:
In Splatoon 2, using this special makes the player perform a large jump (though they're susceptible to attacks during this animation) followed by a strike to the ground, causing an ink explosion around them. Using it from the air gives the player a chance to hasten the animation by skipping the jump. Being in the radius of this explosion in Splatoon 2 splats you instantly. In Smash, this could function similarly to Magic Burst, but with a much smaller radius, and slightly less knockback. It'd also deal a single hit of damage in contrast to the multiple hits of Hero's Magic Burst.
Inkjet:
This gives the user an ink-propelled jetpack that leaves a trail of ink, and a blaster holding 6 shots (with a slow firerate but huge damage). The trail of ink leaving the jet's exhaust can also deal damage to enemy players. When the special ends in Splatoon 2, the user performs a large jump - with their destination being marked by a reticle. This would function identically in Smash.
Bubble Blower:
This special gives the user the ability to fire 3 large bubbles, which slowly move & bounce in the direction the player fired them. They grow when attacked by your team, and shrink when attacked by the enemy team. If they grow large enough, they explode dealing lethal damage to the surrounding enemies. This would allow for some unique kill setups in Smash with the Octolings.
Music, stages, skins, taunts, assist trophies and other miscellaneous things that could be included with this pack:
Taunts:
Up Taunt - Octoling takes out a CQ-80 and activates it. A random memcake will appear. The possibilities are Iso Padre, Marina, Pearl or Captain Cuttlefish.
Side Taunt - Octoling takes out a curling bomb and examines it.
Down Taunt - Octoling takes out a CQ card, and "+3000" (green text) appears above their head.
--
Victory theme:
https://www.youtube.com/watch?v=IzRK1ve4oy4
If a match is won without dying once, this theme plays instead:
https://www.youtube.com/watch?v=jRFo7-qIAPA
Victory Screen #1: Octoling is seen holding out a memcake. In team battles, this is the pose used if the Octoling is not the MVP.
Victory Screen #2: Octoling performs the same victory screen seen in the Octo Expansion, though the background is the results screen. When the Octoling boards the Deep Sea Metro, it trails off and the camera is left behind.
--
Skins:
Agent 8 - Default Girl
Agent 8 - Default Boy
Sanitized Octoling Girl
Grizzco Worker Boy
Pearl-based Girl
Marina-based Boy
Forge Outfit Girl (with Golden Toothpick) (Octoling Hairstyle #2)
Toni Kensa Outfit Boy (with Golden Toothpick) (Octoling Hairstyle #2)
Stage:
Ruins of Ark Polaris. A moving stage that transfers between the mainstage & the shoreline. Mr. Grizz will announce what boss will appear next. You may encounter a Flyfish, a Steelhead or a Griller. You can also ride on the rails - they'll work like ice (similiarly to the Summit stage), except you can only jump when you board them.
Music:
Shark Bytes (Remix)
#8 Regret (Remix)
#14 crush (Dedf1sh)
Octarmaments (Turquoise October)
Splattack (Octo) (Dedf1sh)
Nasty Majesty
Ebb & Flow
Fly Octo Fly
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As well as 2 songs from the base game from Splatoon 2:
Tidal Rush (DJ Octavio feat Callie vs. Marie)
The Girl From Inkopolis (Turquoise October)
Overall, I feel that the Octolings could provide Smash with a completely unique fighting style that would definitely see a large playerbase because of the size of the Splatoon fanbase. This thread is still under construction, so I'll fix some of the formatting later!