From what I've played so far, it appears Team Rocket is the main antagonist, having made a comeback after being disbanded, along with a Rival (similar to Gary in other games) that you meet towards the beginning of the story.
Team Rocket. They always are in any Kanto pokemon game
Team galuctic
Team Plasma
get a lot of coins in the game corner and then buy it from one of the guys next to the game
Aura Beam is in Pokemon HeartGold.
That is impossible in Pokemon HeartGold and SoulSilver.
No, you cannot sell eggs in Pokemon HeartGold.
You need to mate the Pokemon with a Ditto.
Usually just beat the gym or the bad guys and you will be fine
Yes.
There is no best Pokemon on Pokemon HeartGold.
there is no Pokemon Mansion in Heartgold.
There is only old, good, and super rods in Pokemon Heart Gold.
They are not in Pokemon HeartGold
where is the pokemon transfer lab in heartgold
get a lot of coins in the game corner and then buy it from one of the guys next to the game
none out yet. Roms are bad so go to jail
No, but you can trade Pokemon only in HeartGold to Black
Aura Beam is in Pokemon HeartGold.
That is impossible in Pokemon HeartGold and SoulSilver.