You have to complete your pokedex the oak gives you a call
You must have the National PokeDex to capture Heatran.
you cant
You go round all of sinnoh and see every pokemon. It is easy to complete but will take a long time. You will not be able top catch them all without trading but you can complete it without trading
eterna forest 10%
You have to travel around Sinnoh to complete the Pokedex.
U Will Need Gameshark Codes To Complete The Pokedex In Pokemon Emerald.
No, not without action replay or hacking unfortunately. I hate to say it, but sorry. There were wi-fi events but you missed them.
You can catch them on Iron Island once you have the National Pokedex. You get this by seeing all the Pokemon on the Sinnoh Pokedex.
you can catch them on Pokemon pearl, diamond, platinum, and one or two are found in Pokemon rangers and can be transferred to your Pokemon pearl/diamond games. Also Pokemon can be transferred from and of your Pokemon DS games, such as Pokemon leaf green. To transfer your Pokemon from a gameboy game you have to go to the palpark which you get after you complete the sinnoh pokedex.
It's impossible to complete the pokedex in a couple minutes without cheating you have to do alot of training, trading and breeding which takes hours of work.
Once you have completed the pokedex I think you should try and evolve them all and then get them all to level 100 although its impossible to complete the pokedex without an action replay