Players will have the chance to battle and capture Mewtwo with the Ghost-type move Shadow Ball in upcoming EX Raids. In fall 2017, Pokemon Go introduced the EX Raid, a special type of Raid in which players could battle a special powerful Pokemon. Players had to obtain an invite to an EX Raid, either by participating at a normal Raid at an EX Raid eligible gym or by getting an invitation from a friend who had an EX Raid Pass. When Mewtwo was first introduced to the game back in 2017, it was only accessible via EX Raids for nearly a year.
Now, Mewtwo has returned to EX Raids, and the Pokemon will once again have the move Shadow Ball - a powerful Ghost-type Charge attack. Because of Mewtwo's overall stats, a Mewtwo equipped with Shadow Ball was considered the strongest Ghost-type attacker in the game until the release of Giratina last year. While Shadow Ball Mewtwo is no longer the powerhouse it once was, this still marks a rare opportunity to obtain this particular moveset, as it's no longer available through normal Raid Battles. Please note that players will need to beat Mewtwo in an EX Raid and then capture it in order to obtain the Shadow Ball Mewtwo moveset. Using a Charge TM will not unlock access to this move.
If you want the chance to grab a Shadow Ball Mewtwo, you'll need to find an EX Raid eligible gym and then participate at a Raid at the gym. EX Raid eligible gyms are marked in the upper corner of the gym and tend to be located in spots with no potential access issues or places where a large crowd might draw complaints. Look for EX Raid gyms in parks and other public spaces - or seek out a local Pokemon Go group and ask for help.
The first EX Raid invitations will be sent out later this week. Good luck, Pokemon Go trainers!