Name: Arbok
New Stats: 85/120/105/75/90/115 BST 590
New Typing(if any): Poison / Dark
Movepool Addition(s): Knock Off, U-turn, Recover, Hypnosis
New Abilities(if any): Intimidate / Shed Skin / Strong Jaw (HA)
Justification: Has access to all Fang/Biting moves and snakes are known for fangs and being able to swallow almost anything so Strong Jaw makes sense. Also learns a lot of Dark type moves and snakes are known for being sneaky so Dark type easily fits. Increased physical stats go with how it intimidates foes and snakes seem pretty fast animals so an increase in speed makes sense. Recover goes with how Arbok in Adventures manga heals from being cut in two- this gives it more longetivity as a Coil setup booster. Hypnosis because it 'transfixes prey' with its body's facial patterns.
Niche in OU: With only 1 weakness and a boost in Speed, Attack and Defense, Arbok can abuse Coil better with the upgrades and has nice synergy with each ability. Intimidate adds more Defense during switch-in, Shed Skin can remove pesky Burns and Strong Jaw adds more power to a new STAB Crunch as well as elemental fangs. Coil + Gunk Shot already has great synergy together and a more useful secondary STAB could just be the thing to give it more use- Sucker Punch is useful priority, Pursuit is for trapping while Knock Off is great utility. Recover is appreciated and definitely a boon for defensive sets- and is an alternate option for recovery if Shed Skin/Rest is too unreliable for you. A fast U-turn can be an option for Intimidate sets if you're not using Coil to setup. Can also use Coil+Dragon Tail for pseudo-hazing.
Name: Garbodor
New Stats: 120/95/105/70/95/105 BST 590
New Typing(if any): Poison / Steel
Movepool Addition(s): Switcheroo, Roar, Iron Head, Slack Off
New Abilities(if any): Stench / Moldbreaker / Aftermath (HA)
Justification: Poison/Steel because of the industrial garbage components of its design. Moldbreaker is a nod to its visual design of garbage breaking the trash bag on its body, thus the garbage is 'breaking the mold'. Also its design is very unique in a love it or hate it way so there's that meaning of the phrase lol. Roar because just look at its mouth- doesn't it look like 'RAWRRR!!'? Slack off fits its visual design- living in dumps.
Niche in OU: With new resistances from Steel and the boost in defenses/speed, Garbodor could be an interesting support/tank-ish Pokemon. It has access to hazards such as Spikes/Toxic Spikes and can bypass Magic Bounce thanks to Moldbreaker. It also has access to new support moves like Switcheroo to pass an undesirable/'garbage' item like Toxic Orb/Black Sludge to an opponent and Roar for pseudo-hazing. Roar in particular is interesting as its resistances help soften damage and with Moldbreaker, it allows situations such as Levitating mons forced into battle with Roar to be affected by Spikes. Iron Head for STAB and Stench/Body Slam/Iron Head flinch shenanigans.
Name: Weezing
New Stats: 80/90/130/110/95/85 BST 590
New Typing(if any): Poison / Dark
Movepool Addition(s): Whirlwind, Defog, Recycle, Sucker Punch
New Abilities(if any): Levitate / Flash Fire / Flare Boost (HA)
Justification: Spreading black smokescreens in battle to poison and reduce visibility? Sounds like a Dark-type attacking style to me. Weezing also gets used by Ninjas/Koga as living smokescreen/smokebombs so Dark pairs well with the Ninja tricks. Also one of the few instances where a levitating Poison/Dark works in terms of flavour. Flash Fire/Flare Boost is connected to "where there is smoke there is fire"- and could be an interesting user of Flare Boost. As Weezing deals with air and can blow smoke, it can blow air so Whirlwind and Defog makes sense. Sucker Punch means Surprise Attack and Weezing can definitely do that within a smokescreen. Recycle because air moves through a cycle? (Okay I just wanted some Recycle+Sitrus berry+Belch shenanigans)
Niche in OU: No weakness Weezing- slightly balanced by the fact it only has Pain Split as recovery. It has resistances to Ghost/Dark/Grass/Poison and immunity to Psychic (and Ground with Levitate). A boost in Special Attack gives it the offensive presence it needs with its Fire/Electric coverage moves. New Dark STAB has better coverage than Poison. Utility moves like Whirlwind has synergy with Toxic Spikes while Defog can be for hazard control. Flash Fire can boost Fire moves and patch up a susceptibility to Burns, making it immune to both Poison and Burn status, while Flare Boost can be an interesting option for a status-absorbing, offensive Weezing- however this leaves Weezing with a Ground weakness.
Name: Seviper
New Stats: 75/130/70/130/70/115 BST 590
New Typing(if any): Poison / Dragon
Movepool Addition(s): Gunk Shot, Draco Meteor, Dragon Rush, Fire Blast
New Abilities(if any): Shed Skin / Infiltrator / No Guard (HA)
Justification: Seviper is very offensive-orientated in design so No Guard makes sense since it bears scars from Zangoose fights while the sword tail focuses on attack. Dragon moves like Draco Meteor are a given with the new typing. Fire Blast is an upgrade to Flamethrower which it already learns.
Niche in OU: No Guard Gunk Shot/Dragon Rush will hurt with those offensive stats. Seviper's main focus is to attack, attack and attack with that Speed. Life Orb is preferred for versatility, especially to punish Fairy switch-ins who think they are immune to Dragon STAB with Gunk Shot. Steels can be punished with a no-miss Fire Blast/Earthquake- these coverage options and immediate power separates it from Arbok.