The Nuzlocke Challenge is easily the most popular alternative way to play through the Pokemon games. One of the most popular regions to Nuzlocke is Sinnoh because the games set there really force players to strategize. Yes, a lot of people complain about Candice having a Fighting/Psychic-type on her team, but this forced players to develop a strategy other than "Fire beats Ice so Fire wins."
So if you're going to do a Nuzlocke run in one of the hardest Pokemon regions, you're going to need to find teammates that will make the journey as easy as possible. And the Pokemon on this list will make any Sinnoh journey a piece of cake.
This list includes Pokemon that can be encountered in the Sinnoh region, not just Pokemon that were introduced there. So any Pokemon from Kanto, Johto, or Hoenn that are part of the national dex will be included.
11 Bibarel
Bidoof and Bibarel are the butt of many jokes since they're seen as weak early route rodents and look, well, pretty doofy. But Bibarel is actually a lot more useful than just being the Pokemon you teach all of your HMs to.
Bibarel gets access to two fantastic abilities: Simple and Unaware. Unaware is great because it completely ignores an opponent's changed stats, so if you go up against a 'mon that keeps spamming Double Team, you can still easily take it out. Simple is the complete opposite, doubling all of your stat changes. This pairs incredibly with boosting moves like Swords Dance and Curse. Bibarel is by no means the best Pokemon in the game, but it is incredibly underrated.
10 Gastrodon/Quagsire
Water/Ground is one of the best dual typings in the game with immunity to Electric-type attacks and only one weakness: Grass. Gastrodon and Quagsire take this even further by having the abilities Strom Drain and Water Absorb, also making them immune to Water-type attacks. This means that both Gastrodon and Quagsire are incredible pivot Pokemon. Well, in generations five through eight at least.
In generation four, Storm Drain only redirects Water-type attacks and doesn't make Gastrodon immune. In this case, Gastrodon is a lot worse and you should go with Quagsire. But you honestly can't go wrong when you're using a Pokemon that only has one weakness.
9 Chansey/Blissey
Defensive Pokemon are incredibly important in order to switch into the more fragile attackers. And if you want a great special wall, you can't go wrong with Chansey or Blissey.
Blissey has a massive base 135 Special Defense and an even higher 255 HP stat. However, Chansey can actually be even more bulky than its evolution if it is holding the Eviolite item. The only issue with these Pokemon is that even though they are more common in Sinnoh than in Kanto, they are still pretty hard to find. But if you can find one, you'll be able to handle any Special Attackers, no problem.
8 Luxray
One of the most important abilities you can get in a Nuzlocke run is Intimidate. This will lower the opponent's Attack making it easier for your own teammates to switch in and out. Fortunately, you can get access to a great Intimidate user early on with the Luxray line.
Luxray is a pure Electric-type meaning that it only has one weakness: Ground. It also has a great Attack stat that takes advantage of its good coverage with moves like Wild Charge, Crunch, and all of the elemental Fangs. The only downside is that Luxray has middling Speed, but Intimidate remedies this by giving Luxray a bit more bulk. So long as you don't send it out against Bertha and her ground types, Luxray is going to be a great member of any team.
7 Kadabra/Alakazam
Alakazam is an incredibly powerful glass cannon with a 135 base Special Attack and 120 base Speed. And Kadabra is fantastic as well with stats just below Alakazam's. They're one of the best Pokemon in the Kanto region and are also incredibly effective in Sinnoh.
However, they're not quite as good as they were back in Kanto. Alakazam dominated so much because there were little to no counters when Gen 1 was developed. In Sinnoh, there are a ton of counters that could easily take them out, like Weavile and Spiritomb. Kadabra and Alakazam are still great, but they'll never live up to the standards set in generation one.
6 Staraptor
Luxray is great as an Intimidate user, but it isn't the only Pokemon with that ability in the early routes. While Starly may not have it at first, it will soon evolve to Staravia and Staraptor. And Staraptor is a true menace.
Essentially, it is a Flying-type Luxray but better. It has the same Attack, but is faster and gets access to great attacking and coverage moves like Double Edge, Brave Bird, and Close Combat. And those moves get even stronger if you get access to its hidden ability Reckless which increases the power of recoil moves. Staraptor is the best fully evolved early route bird and easily justifies its place on any Nuzlocke team.
5 Crobat
Zubat is not a great Pokemon, but it is common. Golbat is also not particularly good. But Crobat is fantastic with a blistering 130 base Speed and slightly above average stats in everything else. What makes it so suited for Nuzlockes is not just its speed but how early you can get it, and its quad resistance to Fighting and Grass-types.
You'll run into Zubat before you even get to the first gym and you'll get Golbat by the time you get to the second. Since Crobat evolves by friendship, you will easily have built up enough steps and events to get Crobat right after Gardenia. You could also just run back and forth grinding its friendship a bit. This means you'll have a fully evolved Pokemon to help you on your journey and wreck shop.
4 Lucario
Stoic, intense, and blue, Lucario is one of the coolest Pokemon ever created. And it just so happens to be wonderful in a Nuzlocke! Lucario has nine resistances and an immunity to Poison-type attacks, so it is especially useful against any Team Galactic members. Lucario is also an adept mixed attacker with high stats in both Attack and Special Attack while also having decent Speed.
But what makes Lucario especially great is how easy it is to get. Once you get to Iron Island, just help Riley get rid of the Team Galactic members and he'll give you an egg. This egg will hatch into Riolu, guaranteeing a powerful Pokemon for your team.
3 Garchomp
Garchomp has been one of the strongest Pokemon of all time since its debut in Diamond and Pearl. With a great Speed and monstrous Attack, the only real downside to using it is that its first form, Gible, isn't available until after you defeat Byron. And while all three forms are weak to Candice's Ice gym, Garchomp can easily sweep through the final gym leader and the entire Elite Four by itself.
All you need to teach Garchomp is Rock Slide, Earthquake, and Fire Blast and it can easily handle anything in front of it. So long as you keep it away from Ice-types, Garchomp makes the late game a piece of cake.
2 Infernape
In any Pokemon game, the most important decision you'll make is your starter and the Sinnoh region has some of the best choices out there. Empoleon has a unique Water/Steel-typing and Torterra is an absolute tank. But for a Nuzlocke, they both pale in comparison to Infernape.
Infernape has a massive advantage against half the gym leaders and an Elite Four member, not to mention being one of the few Fire-types in the region. Seriously, there are only four total lines of Fire-type Pokemon. Plus, Infernape can be both a physical and special attacker with a base 104 in both. Infernape is really your only choice of starter Sinnoh region.
1 Gyarados
That's right. The best Nuzlocke Pokemon in Kanto is also the best in Sinnoh by a long shot. Oddly enough, the later generations just make Gyarados even better.
Not only does it still have a Ground immunity and access to Initimidate, but Gyarados also gets a much deeper move pool with access to moves like Stone Edge, Ice Fang, Bounce, and Power Whip. And if you're playing with hidden abilities, you also get access to Moxie which increases its Attack every time it knocks out a Pokemon.
Gyarados is immensely powerful and almost a guaranteed encounter with the Old Rod. It is by far the best Nuzlocke Pokemon out there.