step up, snap ya back
Arbok is a fantastic offensive check to Hitmonchan and Grass-types that sports decent Speed, Attack, and movepool, all of which together can make it hard to deal with. Arbok fits best on Choice Band spam teams that rely on overwhelming the opponent with strong and fast physical attackers, but Arbok also fits well on balance teams through spreading paralysis with Glare and making the most of Intimidate. The only true downside to Arbok is that every team is naturally prepared for it, as many Pokemon in NU are able to withstand its STAB Sludge Bomb and coverage moves with ease.
name: Choice Band
move 1: Sludge Bomb
move 2: Earthquake
move 3: Rock Slide
move 4: Double-Edge / Hidden Power Ghost
item: Choice Band
evs: 4 HP / 252 Atk / 252 Spe
Arbok faces stiff competition with Golbat for the role of offensive Choice Band Poison-type, but Arbok has Intimidate and a better coverage movepool than its bat brethren with Earthquake and Rock Slide at its disposal. Arbok has phenomenal neutral coverage between its STAB, Earthquake, and Rock Slide, leaving the last slot to be largely filler. Double-Edge is a great safety move with high power, while Hidden Power Ghost is Arbok's best move for Haunter and Chimecho looking to switch into Arbok and force it out. Choice Band Arbok fits best on balance and offensive teams as an offensive Hitmonchan check and on those teams that would prefer the extra buffer of Intimidate over Golbat's immunity to Ground-type moves and Spikes.
[ADDITIONAL SET COMMENTS]
A Jolly nature is highly recommended to outspeed Hitmonchan and Kingler, as well as Speed tying other maximum Speed base 80s such as Glalie, although an Adamant nature is usable if more power is desired considering Arbok's Attack is only decent. Giga Drain is a decent option in the last slot as a nasty surprise for Relicanth and Graveler, but has little use outside of those targets. Body Slam is also usable in order to spread paralysis, but Arbok is better off going for the KO with Double-Edge and its other coverage moves.
This set needs teammates to switch into Sableye and Mawile, as they can switch into many of Arbok's moves relatively for free and proceed to set up. Flareon is a good Pokemon to pair with Arbok as it can easily switch into and force out both of these threats, as well as provide Arbok with healing from Wish and a safe switch in with Baton Pass. Arbok will deal a ton of damage to Steel- and Rock-types with Earthquake, but will need teammates to switch into Flying-types and Chimecho for when Arbok gets locked into it. Mawile makes a good teammate for this reason, and it can Baton Pass Substitutes and Swords Dance boosts to Arbok to make it far more threatening. Offensively, Arbok pairs well with other Choice Band users to keep up offensive pressure on the opponent and wallbreak to create opportunities for a teammate to sweep. Vigoroth in particular loves the holes that Arbok can punch into the opposing team and its ability to switch into and threaten Hitmonchan, and in return can sweep with Bulk Up once the opponent's Rock- and Steel-types have been sufficiently weakened.
name: Glare Support
move 1: Glare
move 2: Sludge Bomb
move 3: Earthquake
move 4: Screech / Haze
evs: 4 HP / 252 Atk / 252 Spe
This set takes a conservative approach to Arbok, making the most of Intimidate and Arbok's access to Glare to spread paralysis and soften the opponent's team. Glare should be used with impunity in order to slow the opponent's team as much as possible to open up a sweep for one of Arbok's teammates later in the match. Sludge Bomb and Earthquake keep Arbok's decent neutral coverage, allowing it to apply offensive pressure and make it hard for the opponent to switch into it. Screech is a great phazing move and can make it even harder for the opponent to reliably respond to Arbok; Mawile and Chimecho are both easily 2HKOed at -1 (due to Intimidate) and -2 with the appropriate move, respectively. Alternatively, Haze can prevent the opponent from using Arbok as setup bait. Arbok is also one of the fastest users of the move, allowing it to switch into and eliminate the boosts of several Pokemon many others cannot, such as Calm Mind Chimecho and Bulk Up Hitmonchan.
[ADDITIONAL SET COMMENTS]
Arbok's Speed is less important when using this set due to Glare paralyzing the opponent, making Adamant the preferred nature so that Arbok can guarantee the OHKO on offensive Bellossom with Sludge Bomb. Speed is still maximized to allow Arbok to paralyze as much as possible before taking a hit from the opponent; however, if you prefer to make the most of Arbok's resistances, the Speed EVs can easily be moved into HP. With only 16 Speed EVs, Arbok will still be faster than maximum Speed Adamant Mawile and other neutral nature base 50s. Refresh is usable in the last slot to keep Arbok free of status, although Arbok is already immune to the most common status in NU in Toxic.
This Arbok set fits well on teams with slower sweepers that appreciate paralysis being spread on the opponent's team. In particular, Arbok tends to lure in Chimecho, Haunter, and Sableye, making Swords Dance Tropius, Bulk Up Hitmonchan, and Bulk Up Vigoroth good teammates to pair with Arbok. Arbok is also a good teammate to those Pokemon that are weak to Hitmonchan and Grass-types, such as Rock-types like Relicanth and Pupitar. Finally, Arbok needs a teammate that can take on Chimecho and the Steel-types looking to absorb Arbok's Sludge Bomb, making Murkrow, Whiscash, and Flareon good teammates to keep up offensive pressure against the opponent.
A physically defensive RestTalk set with Shed Skin can be run to make the most of Arbok's Fighting- and Grass-type resistances, but Arbok is pretty reliant on Intimidate to make up for its rather lackluster Defense stat and such a set is ultimately outclassed by Swalot. In the same vein, a Protect + Toxic set is usable, but Arbok's access to Glare is its biggest niche and Golbat ultimately does this set better due to its higher Speed and better overall defensive typing. Arbok's movepool is pretty lacking, but does feature some neat moves such as Torment, Pursuit, and Spite, but Arbok is simply better off attacking the opponent and typically won't be scaring out anything weak to Pursuit anytime soon.
[Checks and Counters]
Physically defensive Sableye is the safest switch-in to Arbok as it is only 3HKOed at best by a Choice Band-boosted Earthquake and can stall Arbok out with Recover and Seismic Toss even if it gets poisoned by Sludge Bomb. Steel-types are your next best option as they are immune to Sludge Bomb and resist Arbok's other coverage moves apart from Earthquake. Golbat will take a lot of damage from Rock Slide and Double-Edge and does not want to be paralyzed by Glare, but can otherwise safely switch into Sludge Bomb and Earthquake and threaten back with its Flying-type STAB moves. Rock- and Ground-types like Relicanth, Whiscash, and Sudowoodo can easily switch into Sludge Bomb and threaten back with a super effective Earthquake. Chimecho and Haunter have a tougher time switching directly into Arbok but can easily KO back with Psychic. Finally, Arbok's bulk is not exactly stellar, meaning it is pretty easily O-2HKOed by most strong attackers in the tier such as Choice Band Pidgeot, Plusle, and Raticate.