You\'ll need a level 60 water pokemon.
Have your water pokemon know 4 water attacks. Get a Link Box,a silver spike, and Food
items if you need it. Equip the water pokemon with a Friend Bow. Go to Magma Cavern alone
and save at the statue when you get that high. When you get to the Warp Point on the 2nd
floor after the statue, link together the water attacks. Also heal to full HP. Go into the
Warp Point. After Groudon is done talking, throw the Silver Spike. Groudon will take
damage and move forward. Use the linked moves until it faints. When it does, if you still
have full HP, Groudon will ask to join you. Enjoy Groudon.