This video is a successful run of the Mighty Mewtwo Showdown Event Raid in Pokemon Scarlet/Violet for the Nintendo Switch. Completing the raid allows you to catch the Mewtwo, and it will have the Mightiest Mark. Any Mews that successfully complete the raid will also be given the Mightiest Mark. I am aware that using the Master Ball on this raid could be seen as a waste, but I simply like how it looks with Mewtwo.
Details on the raid can be found here: https://scarletviolet.pokemon.com/en-...
This was the most difficult event raid yet and definitely requires some set up beforehand, but I was able to complete it with randoms. Ideally you have a few support Mews that can lower Mewtwo's accuracy and special attack with Mud Slap and Struggle Bug respectively while keeping DPS Mews up and healthy to maximize their attack. It is very important for one of the Mews to use either electric or misty terrain before Mewtwo's shield is broken as otherwise it will try use rest to regain all of its health.
I ran this support build:
Nature: Bold
EV's: 252 HP and 252 SpD
Struggle Bug
Mud Slap
Life Dew
Helping Hand