first you must bring allthe regi's from another game then you must battle and catch it like any other legendary
You must have all three of the 'Regi' pokemon. Regice;Regirock;and Registeel. Then go through the ice maze; and there should be a regigas standing there. Have some poke balls; and strong pokemon. Regigas is encountered at lvl 70. (correct me?)
first take the amethist then exit the labyrint
By redigas, do you mean Regigas? And no Regigas is a legendary. No Pokemon evolves into it.
There is no Pokemon named regigas. so there is no code.
you have to go to mystery gift and go to wi-fi connection and you will get a regigas gift from the pokemart.
Normal type
you can't
It will be at the hippowdon temple
aegis cave
Trough
you have to connect with other game versions
in the temple place in snowpoint city