Celebi

Grass

With its access to Nasty Plot and its expansive movepool, Celebi is a viable special wallbreaker that is capable of dealing with common threats to Grass such as Poison- and Steel-type teams. Its Psychic typing helps Grass-type teams deal with Poison-type teams, as Celebi can check Pokemon such as Mega Venusaur, Nidoking, and Toxapex that are otherwise a pain for Grass-type teams to deal with. On the other hand, the combination of Earth Power and Hidden Power Fire lets Celebi threaten common Steel-types such as Heatran, Mega Scizor, and Ferrothorn. Natural Cure lets Celebi freely absorb status moves such as Toxic and Thunder Wave for its teammates. Celebi's good bulk and handy resistances allow it to tank hits from Pokemon such as Kommo-o and Excadrill. However, Celebi is weak to common coverage types such as Fire and Ice, and its weaknesses to Dark- and Bug-type moves can be taken advantage of by U-turn users such as Greninja and Tapu Koko and Pursuit trappers such as Tyranitar. Furthermore, an average base 100 Special Attack prevents Celebi from breaking past common threats such as Alolan Muk and Jirachi without boosting its stats; however, it can break past them with a +2 Tectonic Rage. It also has an average Speed stat that allows it to outspeed some threats to Grass-type teams such as Nidoking but causes it to be outsped by a majority of the threats to Grass such as Blacephalon, Mega Pinsir, and Landorus.

Psychic

Celebi's wide movepool and decent base 100 stats across the board make it a versatile option for Psychic teams that can act as a setup sweeper or bring a wide range of utility options to the team. By using Nasty Plot to boost its otherwise unimpressive Special Attack, Celebi is able to counter Steel teams with a combination of Hidden Power Fire and Earth Power, turning the tables on a normally difficult matchup. It also has access to a great supportive movepool with Stealth Rock, U-turn, and Healing Wish, giving it both many ways to help its team and unpredictability. Celebi has great mixed bulk, recovery, and a typing that grants valuable resistances to Ground, Electric, and Water and lets it wall almost the entire standard Fairy team, another strong type that Psychic can struggle with at times. Celebi is also a great Pokemon for taking on Water- and Ground-types as a result of its STAB Giga Drain. However, that typing can come back to hurt Celebi, as it is weak to a large number of types that are common coverage, including Fire and Ice, and especially weak to Bug-type moves like U-turn. While Nasty Plot helps alleviate Celebi's damage problems, it has awful damage output without a boost due to its below average Special Attack and its moves' poor Base Power, so it can still find itself walled even after boosting once or twice. Celebi faces a lot of competition in the utility department, as Pokemon such as Mew and Jirachi either bring even more utility options or have a better defensive typing. Nevertheless, Celebi creates its own niche by combining options no other Psychic-type can bring together, such as breaking both Water and Steel or carrying Healing Wish along with its own recovery.