Lopunny

Mega Lopunny is a fearsome physical threat in OU thanks to its high Speed and Attack stats, very consistent STAB combination, especially with its Scrappy ability, and access to solid priority moves in Fake Out and Quick Attack, which lets it chip down and pick off faster targets like Mega Alakazam, Mega Swampert under the rain, and boosted sweepers like Mega Charizard X. Its Speed stat allows it to get the jump on key offensive threats like Ash-Greninja and Tapu Koko. Additionally, it can use the combination of Encore and Power-Up Punch to break past bulky targets that it normally has trouble against, like Toxapex and Clefable, locking them into their recovery moves and using them to set up. However, Mega Lopunny lacks the immediate power necessary to threaten bulkier structures, and its frailty and lack of longevity leave it unable to safely switch into neutral attacks, forcing it to rely on its teammates to come in safely. Not to mention, it is vulnerable to being picked off by priority moves like Ash-Greninja's Water Shuriken and Weavile's Ice Shard at low HP. Additionally, its reliance on contact moves leaves it susceptible to being worn down by Pokemon that have abilities and items that can afflict it with chip damage, such as Garchomp and Rocky Helmet users like Tornadus-T and Zapdos, and it also risks getting crippled with status by Static and Flame Body.