Kingdra

Kingdra has insane late-game potential thanks to how strong its Sniper-boosted critical hits are. The amount of Pokemon in NU that can contend with Kingdra's Water + Dragon coverage is low, and the amount that can meaningfully threaten Kingdra in return is even lower. Kingdra suffers, though, from taking multiple turns to fully set up, which gives the opponent a bit of time to prevent it from taking the game over. Additionally, many of the Pokemon it'd like to set up against, namely Vaporeon, Talonflame, and Arcanine, commonly run Toxic, which severely compromises its ability to clean late-game. Lastly, despite being one of the few offensive checks to Inteleon and Starmie, Kingdra offers very little defensively compared to other Water- and Dragon-types like Vaporeon, Alolan Exeggutor, and Guzzlord, meaning it requires a good amount of defensive teambuilding support.