His Mind's Eye was where his soul qi was stored. Over time, it had evolved from a world of golden fog to one filled with a thick ocean of what looked like melted gold.
With the exception of when Dyon activated his halo, his soul didn't have bottlenecks like what his qi did with his meridians. However, this was because he directly expelled his qi from his Mind's Eye, to his surroundings, and only then manipulated it into the technique or array he wanted.
It was impossible to do this with normal qi because it wasn't as pure. In addition, qi techniques required very specific circulations within the body. If it was expelled first, it would be very crude. This was because, once again, normal qi was not as pure and as such could not communicate with the heavens as easily as soul qi could.
'Wait… my halo.'
