Mega Alakazam has now the ability to appear in Mega Raids in Pokemon Go. It can be one of the more powerful Psychic-type Pokemon, giving you a significant boost in five-star raids. It's quite possible you'll want to fight it down in a Mega Raid, giving you a chance to develop one yourself.
How to beat Mega Alakazam
Mega Alakazam is a Psychic-type Pokemon that will be weak against Bug, Dark, and Ghost-type moves, but it is strong against Fighting and Psychic-type attacks. You can also use Ghost-type moves, but they might be riskier for you since Mega Alakazam can also use the Ghost-type charged move Shadow Ball.
Hydreigon, Darkrai, and Gengar will be the best Pokemon to use against Mega Alakazam.
Hydreigon is a Dark and Dragon-type Pokemon. Having a powerful Hydreigon in their roster if they participated in the Deino Community Day, you'd be surprised that many trainers would have it. The best moveset to teach Hydreigon is the fast move Bite and the charged moves Brutal Swing and Dark Pulse.
Next up, we have Darkrai, the mythical Dark-type Pokemon, which frequently appears in five-star raids at least once a year, giving everyone multiple opportunities to catch it, and you likely have a few from the previous year. The best moveset to teach Darkrai is the fast move Snarl and the charged moves Shadow Ball and Dark Pulse.
Gengar is a ghost-type Pokemon that you'd want to teach Mega Alakazam by using Shadow Ball in these battles, but you'll want to teach Gengar the fast move Lick and the charged moves Shadow Punch.
Mega Alakazam will require a team of six Pokemon to fight. Here are a few more options you may consider adding to your roster.
After defeating Mega Alakazam in battle, you will earn Mega Candy for this Pokemon and a chance to catch an Alakazam.