Celesteela

Steel

Celesteela is one of the best Pokemon Steel-type teams can use thanks to its good overall stats and Flying typing, giving it the ability to act as a wall or a bulky attacker. Its secondary Flying typing gives Steel teams a switch-in to Ground-type attacks from Pokemon like Landorus and lets it pressure Ground-type teams immensely, as the recovery from Leech Seed and Leftovers makes it hard to 2HKO for most Ground wallbreakers. Celesteela also provides a decent neutrality to Fighting-type attacks from Pokemon like Mega Gallade. With moves like Leech Seed, Toxic, and Protect, Celesteela can also wear down many offensive Pokemon such as Mega Sharpedo and Landorus. Celesteela can also wear down opposing walls that Steel has trouble with, like Mantine and Porygon2, with its Leech Seed and Toxic combination. Moves like Flamethrower and Giga Drain allow Celesteela to make dealing with opposing Steel-types and Ground-types like Swampert, Ferrothorn, and Landorus. While Celesteela does not take advantage of Beast Boost as often as its other fellow Ultra Beasts do, if it lands a KO it can become much harder to take down because of its defensive boost. However, although Celesteela is a fantastic wall, setup sweepers like Mega Gallade can break past it, and stallbreakers like Mew can wall it. Celesteela also lacks a proper recovery move, making it heavily reliant on Leech Seed and Leftovers for recovery, which can be problematic against teams with Grass-type Pokemon. While Celesteela is a fantastic Pokemon on Steel teams, it still faces competition from Skarmory as a Ground-immune Pokemon, as Skarmory has superior physical bulk to take on Fighting-types that Steel teams would otherwise struggle with and can take on the Stealth Rock setting role, freeing up a moveslot for Ferrothorn.

Flying

Celesteela is perfect on Flying teams as a physically defensive wall due to Gliscor being the best option as a special wall on Flying teams and Skarmory's lack of viability. Celesteela's incredible mixed bulk even without Special Defense investment lets it reliably check Pokemon like Choice Scarf Nihilego and gives it an edge over Skarmory. An impeccable Steel / Flying typing lets it take half the Stealth Rock damage that normal Flying-types do and leaves it weak to only two somewhat uncommon types that are easily checked by its teammates. Celesteela's typing also provides a plethora of resistances, notably to Fairy, Dragon, and Psychic attacks from Pokemon like Mega Diancie, Latios, and Mew. It also gives Celesteela an immunity to Toxic, giving it an excellent matchup against opposing walls such as Chansey. Other traits like a good Attack stat in conjunction with a generally powerful STAB attack means that types like Fairy and Rock will struggle to find a reliable switch-in. Celesteela's great offensive prowess in conjunction with access to Autotomize also gives it the option to run an offensive sweeper set that has the potential to break through common cores found on types like Steel and Water, especially when holding a Metronome. Celesteela's offensive Autotomize set capitalizes on its ability, Beast Boost, which makes it extremely difficult to wall after it gets a KO or two, especially against more offensive teams, and enables Celesteela to quickly snowball out of control against types such as Fairy. Defensive sets can make use of Beast Boost as well: Celesteela becomes extremely difficult for types like Rock to break through after boosting its Defense once or twice. Unfortunately, Celesteela has a crippling weakness to stallbreakers such as Taunt + Will-O-Wisp Mew as well as Taunt + Knock Off Gliscor. Celesteela's recovery in Leech Seed and Protect with Leftovers simply isn't reliable and leaves it vulnerable to Grass-types and forced to spam Leech Seed. Extremely powerful wallbreakers like Landorus and Mega Gallade are difficult for Celesteela to deal with. Landorus can use Gravity to exploit its typing, and Mega Gallade nearly OHKOes it after a single Swords Dance and is frequently run with Healing Wish support, thus receiving more opportunities to break past it.