Ninja Mewtwo

The combo of Mewtwo ex and Greninja complement each other so much so that it can cover a variety of weaknesses found between the 2. Greninja is a very solid pokemon its basic atk hits for decent damage and its ability softens opponents to be in ko ranges even before they hit the active spot. The issue with Greninja by itself is that it does not have a big burst of damage it can throw at the opponent, instead it likes to attack consistently till its foe is down. This is where Mewtwo fits, as its strength is in its ability to throw 150 damage at a single enemy all at once securing knockouts. However, Mewtwo can't knockout everything, Charizard for instance is the foremost problem. Able to shrug 150 damage while threatening a 200-point ko to us in return should it be setup. This is where we circle back to Greninja, they are able to chip Charizard into that sweet spot in order for Mewtwo to take that ko. The other Great benefit the 2 have is their attacks. Each need very little in specific energy, Greninja needing a single water to be effective while Mewtwo needs 2 psychic. This once Greninja has its 1 water all other energy allocation can be fully devoted to Mewtwo. This is also why Kenghaskan is our other main basic. Kangaskhan is meant to be our unmoving wall to stall until our Greninja is throwing its water shurikens and Mewtwo sits and bides its time. The proper use for Mewtwo here is not as the main star, but our finisher most cases. Unlike other Mewtwo variants because our mewtwo is our ace in the final act we aren't as susceptible to losses because we lost 2 ex pokemon or an ex + a basic like Gardevoir. We do lose that ability to fire large attacks each turn but in return we trade up for not being stuck if our Pokémon (Gardevoir line) get knocked out before we even get that chance to accelerate energy in the first place.