Mewtwo is just about as dominant in Pokemon GO as it is in every other game it appears in.
In terms of stats, moves, and just overall performance, Mewtwo is as close to a perfect Pokemon as Niantic can get. It has an overwhelming 300 Attack stat, paired with powerful moves that come with lower energy costs. Ignoring PvP, Mewtwo can single-handedly beat most raid bosses on its own. There almost is no “ideal” moveset for Mewtwo, since it runs so many great options. This is generally a good way to build Mewtwo, though.
Which are the best moves for the most powerful Pokemon in the game?
Both of Mewtwo’s quick moves have their merits, but Confusion is generally better. Psycho Cut generates more energy than Confusion, but the difference is negligible compared to the damage difference. Confusion has a base 20 power, which far outclasses Psycho Cut’s 5 power.
In terms of charge moves, every Mewtwo should have a STAB Psychic move, and a choice coverage move. For the Psychic move, Psystrike is slightly better than Psychic, but both are acceptable.
Both of these moves only require half of the energy bar to use, and have 90 base power. The only real difference between the moves is that Psystrike’s animation ends a tad bit quicker, therefore resulting in higher DPS. Of course, Elite TMs can be scarce, and other Pokemon may need them more. It’s not always necessary to waste the Elite TM on Mewtwo, then, who works fine with Psychic.
Mewtwo then gets to pick from a handful of great coverage moves. From a pure damage standpoint, however, Shadow Ball is the preferred pick. This move has slightly higher DPS than other options like Flamethrower, Ice Beam and Thunderbolt.
Damage isn’t the only thing, though. Trainers also have to look at utility. What Shadow Ball allows Mewtwo to do is become a great counter to opposing Psychic-types. In fact, many Psychic-types, like Deoxys Defense Forme, have Mewtwo as one of their best raid counters, simply because it can learn Shadow Ball. Mewtwo can also counter popular Pokemon with this move, like Metagross and Giratina.
That being said, though, there are certainly opportunities to use the other moves. Ice Beam is good for dealing with popular Dragons like Dragonite and Rayquaza. Flamethrower can break through bulky Steel-types. Focus Blast is a particularly nice option, though, since it hits incredibly bulky Pokemon like Blissey and Snorlax.