In a world graced with superhuman abilities, the most direct approach to defeat an enemy is actually to enhance one's own power.
For instance, if Ian wished to crush the Mountain People and venture to their Holy Ground to acquire data on the Skyfall Spaceship, he only needed to advance to the Third Energy Level, which would easily allow him to overwhelm all of the Rebel Highlanders—though he might not defeat the Ironwing Dragon Flock, the Dragon Worship Cult and the King of the Mountain would help him fend them off.
But the reason it's the most direct rather than the simplest method is that advancing is just too hard.
