I see... that sounds logical, and gives me an idea of what the main issue may be...

[His Crest Stone was likely the source of his considerable (to a human) magical power, but he could admit that he was only using a tiny percentage of its power, if what Sothis said was true about her original capabilities. If he could unlock more of it, he could theoretically draw upon more magical energy... but with that brought risks. It did function as his heart after all, and there was a chance of it going out of control and turning him into a Demonic Beast as well. Hm...]

Not that it brings me closer to a viable solution. I'd rather not accidentally transform myself into a Demonic Beast by recklessly meddling with my- ah, thing. Magical energy.