Do you guys have any ideas on how to make the mirror master pre con better?
It's a very flexible deck, so a lot depends on which direction you want to take it. Assuming you want to keep {Riku of Two Reflections} as your general, lots of mana generation is key. Creatures like {birds of paradise}, {Alloy Myr}, and {Llanowar Elves} are important to copy, because the more of those you have, the more copies of your bombs you can make. Good ideas of what to copy are not just big, scary things, but things with powerful ETB effects. {Aether Adept}, {Mnemonic Wall}/{Archaeomancer}, {Bogardan Hellkite}...