In the rock-paper-scissors format of Pokemon's typing system, it's often difficult to quantify exactly what the strongest Pokemon is, especially when one considers types and match-ups.
The Pokemon chosen here is not only exceptionally powerful but also has type coverage, decent typing and versatility. Truth be told, there are not many Pokemon in Pokemon GO that are even capable of holding a candle to this one.
Note: This article is subjective and reflects the opinion of the writer.
Strongest Pokemon in Pokemon GO
Without a shadow of a doubt, Mewtwo is the strongest Pokemon in Pokemon GO.
Not only does Mewtwo boast the third-highest max CP in the game (at the moment), but much of its stats go straight into attack. This lets Mewtwo decimate opponents without mercy.
Having said that, Mewtwo doesn't totally abandon its defenses. While being a Psychic-type doesn't exactly do the Pokemon any favors defensively, it still has half-decent defense and stamina that allow it to take a few good hits before going down.
Going back to its offensive capabilities, Mewtwo has a lot of options to choose from move-wise. It can learn Charge Moves from a whopping seven different types, including its own. From Flamethrower and Shadow Ball to Ice Beam, Mewtwo can cover quite a variety of threats.
However, Mewtwo's biggest power comes from its Charge Move, Psystrike. This is a phenomenal move, making it totally worth using an Elite TM on Mewtwo. With high DPS, lower energy cost, and STAB (Same Type Attack Bonus), it's hard to find fault with this move. Backed by Mewtwo's more than exceptional attack, Psystrike ends up ripping opposing Pokemon to shreds.
Oh, and Mewtwo can also be a Shadow Pokemon. While Shadow Mewtwo will take more damage, its already absurd ability to deal damage will skyrocket. This makes it a high-risk, high-reward option for any trainer who manages to catch one.