Indigo Plateau. In order to get to them, you need to defeat all eight Johto gyms.
lance
beat elite four rematch
The elite four
Beat the Elite four and the Champion.
The Elite Four Champion in Pokémon SoulSilver Version is Champion Lance.
Legendaries or Feraligatr, Ampharos, and Heracross.
After defeating the Elite Four once, their Pokemon are much stronger than before, and with new Pokemon. There is no new Elite Four to battle, though.
No there's only one elite four.
You have to get an action replay and battle one of the elite four
You wait until you beat the elite four and professor Elm will give it to you when you beat the elite four.
Lv 42 to lv 45
the fourth trainer in the elite four have a murkrow