Treecko

Treecko has a unique niche on offensive teams thanks to its Unburden ability. This allows Treecko to set up Swords Dance, usually take a hit, and consume Berry Juice afterward, thus doubling its Speed and becoming a threatening late-game sweeper. Alongside Treecko's fantastic ability and access to Swords Dance are plenty of useful coverage options, including Acrobatics, Drain Punch, and Rock Slide. Unfortunately, Treecko is extremely frail with a poor defensive typing and is thus vulnerable to super effective attacks, powerful offensive Pokemon, and strong priority. Treecko is also extremely weak before a Swords Dance boost, meaning that it is quite reliant on the move to do any notable damage. It can still struggle to break past some bulky threats after a boost, such as Spritzee, Vullaby, Mareanie, and Foongus, as it isn't extremely powerful even after using Swords Dance. Unburden can also be a rather situational ability in that it only activates once, meaning that upon setting up, Treecko will put itself in an all-or-nothing situation. Treecko also suffers from a slight case of four-moveslot syndrome, as its choice of coverage will either prevent it from hurting Fire- and Poison-types if it uses Acrobatics or from hurting Grass- and Fighting-types if it uses Rock Slide. Lastly, the strenuous team support Treecko requires to sweep can cause the teams built around it to be matchup reliant.