First beat the elite four, Second obtain the national dex and Third deliver the ruby and sapphire to celio and lastly gain the hall of fame sticker from the guy on four island you should now be able to enter cerulean cave where mewtwo is.
you can't.:( but you can trade it from firered or leafgreen but to do that you have to get the national dex by catching 60 pokemon and getting all the items the aide has for you.if you own firered or leafgreen just go to google andtype in how to get MEWTWO. hope this helps:)
mew and mewtow
The strongest pokemon and the powerfull is MEWTOW . you might say Arceus he created the world of pokemon , but he dident create MEWTOW , mewtow created by human , here , the difference between the tow , there is a challenge between these tow . And abuot the new pokemon kyrum his power level of like lugia and others they not on level mewtow and arceus . in my opinion it must become a challenge between these tow to decide who is the strongest in the world of pokemon .
you don't get mewtow in ruby
Go to Cerulean Cave.
The correct spelling for the Pokemon is Mewtwo.
12$ maybe...
in cerulein cave very back
mewtow zapdos moltres articuno mew entei raikou suicune
In Pokemon firered you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.
you must used this cheats at gameshark THE CODE IS : mewtow 30621E6F164FED85
There is no Pokemon convention in firered.