That was a part that Karl had missed in the explanation. He had heard "Soul Energy" and assumed that whatever he could get his hands on was fine.
The Elder had assumed it was only common sense that you used your own Soul Energy to form your Immortal Spirit.
So, he hadn't seen the need to spell it out.
Naturally, Karl had no idea that after binding his Immortal Spirit to all the points of his power Matrix and giving it shape, it was technically finished. It had a shape, it was stabilized, and the Spirit was permanently linked to him, protecting his Soul and Power from attacks.
Without that knowledge, he simply didn't stop, and flooded the Spirit with power until it felt like a proper spectral being, and the power influx slowed.
Finally, he opened his eyes, pleased that he hadn't had to burn through the reserves in the Haint to complete the task.
"Welcome back. How did it go?" The Elder asked slowly.
