Might as well just answer it now. o3o First off; is your "son" in the beginning of the game or the end of the game? It does make a difference because you need HM08 Rock Climb to travel to Spear Pillar, which is only obtainable at the end of the game. If he has, what part of Mt. Coronet is he in? Has he reached the snowy division of Mt. Coronet yet? Be specific. If he's done with all 8 of the gym leaders, here's what you do from the beginning of Mt. Coronet to the end:
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Mt. Coronet
Before going, make sure to stock up on lots of Ultra Balls. Also be sure to have lots of Dusk Balls, which can be found in Pastoria City's Pokemon Mart. The reason is that you'll soon be catching Dialga/Pakia. In addition, you might need (Super/Max) Repels if you don't want to encounter wild Pokemon every few steps. You'll also need a Pokemon that knows Rock Climb. Now fly over to Oreburgh City and head east, entering Mt. Coronet on Route 207.
Surf across the water at the north. Go up the stairs and pick up the Protein. Climb the rocks at the very east and go up the steps. Pick up the Max Potion at the north and also the hidden Ether on the small piece of rock nearby. Go all the way south for an Escape Rope. Go north, then south again. Get outside through the exit temporarily, climb down the rocks, and pick up an Iron. Go back into the mountain and go as far north as you can. Cross the bridge and go south for TM80 - Rock Slide. Go north for a Revive. Now head east to get to the lower level and go inside the cave opening. Go up the steps and you'll be surrounded by three steps on all sides. Take the one on the right for a hidden Max Revive on the southern-most rock. Go back and go north, where you'll battle a Galactic Grunt. Go west and pick up the hidden Super Repel on the corner rock. Fight the Grunt and exit through the south.
Climbing to the Peak
Now you're outside in a snowy environment. The goal now is to climb to the top of Mt. Coronet. Go east, north, and climb the rocks. If you go east into the cave opening, you can go straight up the steps for a hidden Ultra Ball. Smash the rock at the bottom-left corner and pick up the hidden PP Up on the rock that's revealed. Go outside, head west, then south (not through the grassy area). Push the boulder out of your way and continue west. Smash the rock along the way and pick up the hidden Max Potion. Head north and go into the cave opening. Back inside, go straight and climb the rocks. Battle the Galactic Grunt, smash the rock near him, and pick up the hidden Revive. There's also a hidden Ether on a northern rock. Go east, battle the Grunt, and go south a bit to pick up a hidden Escape Rope. Head out again by going east.
Go all the way north for a hidden Rare Candy on the single rock. Go south a bit and go down the steps. Check out the cave opening to battle some Galactic Grunts and pick up a few hidden items, including a Rare Candy hidden in one of the rocks in the lowest level. You won't be able to go into the cave opening blocked by the Galactic Grunt. After they leave later, however, you may go inside to pick up TM02 - Dragon Claw. After that, get out of this cave area.
- Walkthrough from PokeDream.com.