Misdreavus
Voting ban. While Missy helps with the hazard game and is all-around excellent at sweeping and utility, it's way too effective at doing so, to the point of constraining teambuilding. Nasty Plot sets are easy to set up and considering how quickly residual damage stacks up, it doesn't take long until it sets up and sweeps with ease (especially with Naclstack and Mareanie, two passive yet very popular meta trends). Utility sets can mix and match any set it needs for its team, ranging from Thief to Wisp to even Taunt, further amplifying how good it is at the hazard game. Defensive checks like SpD Tinkatuff and SpD Vigoroth do exist, but the former gets worn down in record time and the latter isn't easy to slot on teams. Because Misdreavus is so valuable, revenge killing it isn't simple since it can preserve itself at the end of the game. Overall while not broken, it's too unhealthy to stay in NFE because it's too versatile and effective at whatever it does.

Naclstack
Also voting ban. Salt Cure makes this ridiculously effective at forcing out Pokemon; even super effective Pokemon like Quaxwell and Frogadier aren't able to beat it without suffering massive residual chip. This makes it too effective at keeping Rocks up, especially when paired with Purifying Salt and terrific bulk. Not helping is how well it pairs with Misdreavus and other hazard setters like Frogadier and Toedscool. The best counterplay is Knock Off users, Substitute users, and your own hazards, which isn't exactly easy considering how vulnerable the former two are to Salt Cure and the latter by how not many Substitute users there are. Iron Defense sets, while not oppressive by any means, still add on to the constraint it puts onto the builder. Curse sets have started to pop up in response to Substitute users, allowing it to trade with Missy better. Overall, while not broken, it's still too unhealthy at what it does and mainly serves to worsen the hazard situation in NFE. 

Gabite
Do not ban. Very threatening and versatile, but unlike Misdreavus it can be checked more easily without utility moves like Wisp or Pain Split. The lack of reliable recovery (unlike Naclstack) requires players to exercise more conscience when sending it into the field; hazards are generally used with little risk and with high payoff. Swords Dance sets are manageable considering its merely good Speed tier and power. Gabite also has enough defensive checks like Dunsparce and Quaxwell, so answering Gabite will be less of a hassle unlike Naclstack and Misdreavus. Missy and Naclstack leaving will help open up more counterplay, but Gabite's own qualities help the meta without being too oppressive.