Heatran

Heatran

After picking up the Magma Stone on Route 18, which is only accessible after beating the game and surfing far west of Route 1, you can return to Reversal Mountain. There's a basement area that Bianca showed an interest in during your first visit there. Well, if you have the Magma Stone, you'll run into the legendary Pokemon Heatran there!

Reversal Mountain
Heatran Heatran  Lv. 68