he is strong so train your Pokemon alot.
After beating the 16th Gym leader, you can Catch Mewtwo, and then just train for Red.
you have to beat Red first then go see Prof. Oak. the Pokemon are all on level 5.
He disappears until you beat the Pokemon league again.
after you beat red in Mt.silver
beat elite four rematch
Earn the national Pokédex, go to the mountain where Red is and beat him.
you cant get it in soulsilver but for heartgold you get it from Mr.Pokemon when you deafeat red
pokemon soulsilver-you get it when you beat red then go to prof.oak in pallet town.
beat red and go to prof. oak
You can always catch Groudon. And Rayquaza too.
you cant catch kyogre in soul silver but you need red orb from mr Pokemon but you have to beat red first. oh you can catch groundon though in soulsilver
first you beat all 16 gyms go beat elite four beat red and he will be at the embedded tower after you get the red orb from mr. Pokemon