1.Beat the prime and the poke cup in pokeball, greatball, ultraball, and masterball.
2.Beat petit cup, and pika cup a very good rental team for the pika cup is, Riachu, Gengar, Arcanine, Kadabra, Starmie, and Dratini.
3.Beat all gym trainers, gym leaders, elite four, and Gary.
4.You can now battle the single Mewtwo with up to 6 pokemon, beat him and round two will be open.if you want to go back to the regular stadium press right c when you are in the screen to pick pictures, battle now, or the stadium. Press it again to go to round two.
As you should know round 2 is harder than the 1st.