For actual competitive Mega Rayquaza. Despite being a mega, it can still use held items. Many weaknesses r negated bc of its ability. Good moveset, good stats

Mewtwo. Because he can learn about any move he can learn imprison so any moves mewtwo shares with the target the target cant use the shared move. then transform and mewtwo knows the targets moves. so the target will use struggle and it has recoil so give mewtwo rocky helmet.