How to catch Mewtwo the easy way without master balls
Since the battle with Mewtwo is in a cave, get about 50 dusk balls, and 50 ultra balls. It is recommended that you get more than that. Have about 3 level 65-75 Pokemon that are dark or ghost type, a psychic type, and a Pokemon of any type. Use a dark type attack (like Crunch or Dark Pulse) and two to three psychic type moves (Confusion, the attack move, is recommended for this) to get it's HP in the red. I would prefer a Scyther or Scizor and have it use false swipe to leave Mewtwo with 1 HP left and start throwing Dusk Balls and Ultra Balls.
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