That is up to u to catch em' all. It will take a very long time to do so. some Pokemon will have special requierments to get, such as mystery gifts or migrating.
Mewthree isn't available in any of the Pokémon games.
you will need an ction replay to get cheats eg.one loop capture
you do need cheats
You Need Cheats The Wild Pokemon Modifier.
Arceus cannot be caught legitimately in ANY pokemon game.
You cannot breed Legendary Pokemon without cheats, except for Manaphy with Ditto.
well if you use rom you can search pokemon (verson) rom cheats You can only capture npcs pokemon if you use a ds you cant
You can't get him without events or cheats. For Darkrai, Manaphy and Arceus you need a event to capture him.
No Pokemon game has cheats sorry.
Without cheats they randomly appear in the wild or hatch from eggs.
there are a ton of cheats for Pokemon games but i can't figure some out. : (
No, there are no glitches to capture Mew in Pokemon Emerald. Sry but the only easy way is to buy an Action Replay, the Nintendo Event is over.