Lopunny

Thanks to Scrappy, Mega Lopunny boasts the almost unique ability to use Fake Out against Ghost-type Pokemon like Mega Gengar and Mimikyu, breaking the latter's Disguise for free, as well as granting it unresisted STAB coverage. Furthermore, aside from Ludicolo in rain and Alolan Raichu in Electric Terrain, Mega Lopunny has the fastest Fake Out in the format, making it an extremely reliable user of the move.

It also has additional support capacity in Encore and Fake Tears, allowing it to lock opposing Pokemon into an undesirable move and lower an enemy's Special Defense for an ally.

Mega Lopunny also boasts the ability to heavily damage Incineroar, OHKOing it if unaffected by Intimidate and taking a massive chunk of health even after Intimidate, giving it a niche as a Fake Out user that can pressure it.

However, all things considered, Mega Lopunny has very few options for its moveset, making it very predictable.

Additionally, it has mediocre bulk and relatively low damage output for a Mega Evolution, making it hard to justify the opportunity cost involved with using it as a team's Mega Evolution; if a team wishes to have it, that team must be able to capitalize on its ability to provide disruption support while simultaneously pressuring Pokemon like Incineroar, Snorlax, and Tyranitar.