Mewtwo: I still remember the days when it was the unquestioned best Pokemon ever. As far as I'm concerned, it still is. In the show, Mewtwo proved to be the darkest (first time anyone saw people die in the series) yet the most sympathetic (really, could you blame Mewtwo for wanting to destroy the world given his circumstances?) villain Pokemon's ever had. Mewtwo also holds the distinct honor of being the ONLY villain I've ever shed a tear for. ('Origin of Mewtwo'. Poor Mewtwo, having to watch his only friend die on him, and then being forced to forget he ever knew her... :'( ) In the games, he's unfortunately lost a lot of his former glory. Dark and Steel types were brought in to tame what was then the most feared weapon in the entire game; Mewtwo's STAB Psychic. Still, a 154 Base Special Attack and a 130 Base Speed are to be feared. Sure, KyuremB/W hits harder and Darkrai can keep up without breaking a sweat, but Mewtwo can count on outrunning any non-Scarfed Ice Dragons (or pretty much every Dragon, what with the non-Latis having Speed around the 90's) while still shredding everything in it's path. In short; if you see a Mewtwo, be prepared for a brutal fight.
I wasn't born a Pokémon, I was created; and my creators have used and betrayed me! So, I stand alone!
-Recover/Ice Beam/Grass Knot/Charge Beam (gimmick option)
Item: Life Orb
EVs and Nature: 4 HP/ 252 Special Attack/ 252 Speed. Timid (+ Speed, - Attack)/Modest (+ Special Attack, - Attack)
No attempt to create a funny and hopefully clever pun here, just a straight-up quote from Mewtwo's own mouth describing just what kind of devastation's heading your way. Psychic used to be his most powerful attack, getting STAB and off that very high Base Special Attack...shame it never got much use competitively. But now, Mewtwo has something better, something he's lacked from the beginning; his own signature move. As stated in Heatran's POTW file last Generation, most signature moves tend to be...more gimmick than substance. Not so here; Psystrike hits with a 100 Base Power, equal to an Earthquake on something that doesn't get STAB on it (ex. Haxorus) and has 100 Accuracy. That's win/win in my books, but Mewtwo gets STAB on it...Forget SDGroudon's Earthquake, that's "I wet myself" power, especially with such a massive Special Attack behind it! And it targets the foe's Defense instead of Special Defense, which means Blissy and CMKyogre are going to die trying to stop the original Uber. Aura Sphere and Shadow Ball are for their near-perfect coverage, and the score of Super Effective hits they'll score in the Uber tier. Also, Mewtwo was throwing Shadow Balls around long before they existed; nothing can top that level of coolness. Recover is for recovery (duh). Heal off damage you've taken during your rampage and self-inflicted damage from Life Orb (an easy item to recommend, in this case). There's also something going around the internet about how Psychic and Recover were the only attacks you had to have on Mewtwo. What's that, not concerned about survival? Confident you can get a 6-0 sweep without knocking yourself out from Life Orb's recoil? Alright, alright, I hear you. Ice Beam is here if you really hate Rayquaza, Salamence, and Dragonite (if you ever see the original Dragon in Ubers). Grass Knot is if you must kill Groudon and are confident your other moves can handle everything else. (Aura Sphere slays Tyranitar faster due to a X4 Super Effective hit.) Charge Beam, as stated earlier, is gimmick; that low power won't be making any OHKOs (or any KOs) on it's own, but it'll give you a boost to your Special Attack, making your other moves much stronger. [If someone actually runs this set with Charge Beam in the final slot and wins with this, could you please post to Youtube and notify me?]
Overtyped item is overtyped, as are the Natures by this point. Speaking of Natures, I have to get the following out of my systems. Mewtwo a Timid Pokemon? HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!
EVs, you know the drill by now.
Other Options: Not many. The above moveset can pretty much destroy any-and-everything that either switches into the wrong move or doesn't resist anything here. Thunder is a good, standard attack that's served Mewtwo well. It just, isn't as important what with Psystrike slaying Kyogre (Thunder's main job) without worrying about Calm Mind. Focus Blast is a worse-in-every-way-except-power Aura Sphere; I don't recommend it, but someone probably will. Flamethrower/Fire Blast are for Ferrothorn, Jirachi (if you can catch it out of Rain) and not much else. Maybe Steel Arceus too, but Aura Sphere works better if it's raining.
† I am a Christian and proud of it! Copy and paste this if you are too.†
-Take up thy cross and follow Christ Jesus.
~Don't underestimate my God~
♥I believe in Jesus Christ as my Savior. If you do too and aren't scared to admit it, then copy and paste this in your signature.♥
I don't calculate stat values, I don't use cheating devices, I don't breed my way to perfection, and I don't care about natures. I catch my Pokemon the way they are, and treat them like individuals instead of brainless drones. If you use this philosophy, copy & paste this into your signature. (Started by Tyranitar, "I don't use "uber" Pokemon," edited out by me because I do use "uber" Pokemon on occasion.)