Desmond intended to use another < Leviathan's Wrath - Resonance>, but an unknown strain and exhaustion prevented him from doing so. Desmond was surprised as this was the first time such a thing had happened to him.
After some thought, Desmond understood. "This is called intent exhaustion, the reason why elementalists often build vast repertoires of abilities with different intents as a base. I guess my mana reserves had never been so vast that I would use skills recklessly, so I had never felt it."
To put it in simple terms, the stronger the intent and concepts behind a skill, the more powerful it will be. That was the basis of Elementalist skills. But, the strength of intent also determined the number of times an Elementalist could use a certain skill.
