My lungs were on fire. Each breath felt like inhaling molten glass, but I couldn't afford to stop. Not now.
I channeled a thin stream of essence through my body, careful to keep it subtle enough that I didn't run out of essence. The dark energy flowed through my meridians, strengthening my muscles just enough to keep moving. It was a risk to use my essence like this since it still carried a bit of demonic energy but that would not be noticeable if I control the amount I used.
Too much would be obvious, too little would leave me crawling up the mountain.
The key was in the breathing.
Short, controlled breaths synchronized with each step. Inhale for three steps, hold for two, exhale for four. The rhythm helped maintain a steady flow of essence throughout my body.
I'd discovered early in the climb that distributing the essence evenly was crucial.