you beat the elite four and then go go to the cave next to cerilion city. deep inside it you will find mewto at lvl 70. lower its health and put it to sleep or parilize it and be sure to have lots of ultra balls
mewtwo
Mew can't be catched in Pokemon heartgold, only mewtwo.
The Odd Incense can be found in the Cerulean Cave along with Mewtwo himself.
Do you mean Aura SPHERE? The following Pokemon learn Aura Sphere in HGSS: Mewtwo, Mew, Lucario, Togekiss, Dialga, Palkia, and Giratina.
The cool legendaries you can get in Soulsilver/heartgold are the following: Lugia, Ho-oh, Raikou, Entei, Suicune, Articuno, Moltres, Zapdos, Mewtwo, Latias, Latios (Latios in Soulsilver & Latias in Heartgold), Kyogre, Groudon, Rayquaza (Kyogre in Heartgold, Groudon in Soulsilver & Rayquaza if you have both).
Yes, Mewtwo, Latios and Latias will be in HeartGold and SoulSilver.
mewtwo
Cerulean cave
in cerulean cave at the end
yes, in the cerulian cave
A level 70 mewtwo.
in curelen cave you get mewtwo
You can't catch Mewtwo in Pokemon Diamond and pearl and also platinum. But you can catch Mewtwo in heartgold and soul silver
you dont you battle mewtwo and get out
you dont, its not in HeartGold or SoulSilver, Ho-oh (HeartGold) or Lugia (SoulSilver) take their place. You can also get mewtwo
In Cerealean cave after you get all the kanto gym badges
its in cerulean cave but you have to get all kanto badges first