Go to the Pewter City Museum. Talk to Steven. Talk to the assistant. When you leave, Steven will talk to you. Battle Latios in Pewter City.
Staryu.
Use a thunder stone
use a dawn stone on a female snorunt
You don't use any specific Pokemon. You must have the enigma stone. You could have gotten the stone from a long ago event, which has since passed. With the enigma stone, you take it to Steven to be evaluated in a museum for fossil resurrection. Walk outside to battle latios.
use the enigma stone from an event and its serebii.net not .com i dont know but if you want latias give the doll to the copycat girl.When you come out Steven will talk to you about Latias.Use your poke'gear to find her. She will be roaming Kanto.
there will be a upcoming wi-fi gift, that will give you the enigma stone , which is actually a soul dew. hope this helped !:D that is only for soulsilver and heartgold! *non wifi/non legit way: get an action replay and use the all items code to get an enigma stone which like i said , is actually a soul dew .
You have to use a dusk stone on it to in order for it to evolve
You can evolve an evee which you can find in Goldenrod city.
If you don't have enigma stone, keep it for Latios is my advice
It will only evolve through the use of a leaf stone.
In Pokémon HeartGold, the Legendary Pokémon that you can catch in "HeartGold" are Articuno, Zapdos, Moltres, Mewtwo, Raikou, Entei, Suicune, Lugia, Ho-Oh, Latias, Latios, Kyogre and Rayquaza however you can only get Latios in "HeartGold" via the use of the Enigma Stone and in order to get Rayquaza, you also need to catch a Groudon that was caught in the Embedded Tower in Pokémon SoulSilver.
Gloom -> Vileplume Weepinbell -> Victreebell Exegcute -> Exeggutor