He felt like a large whale, though there is another way to put it, his magical spirit now took the form of a great whale.
The magical spirit swam in the sea of energy, feeding, growing, evolving. The magical spirit and his human reactor were one and the same.
Everyone relied on their magical spirits to obtain extraordinary powers.
The magical spirit was a part of his consciousness.
But some people, even if they could look inward at the reactor, wouldn't feel the presence of the magical spirit. Thus, the magical spirit is a higher order manifestation of the reactor.
He used the magical spirit to explore Origin Power, absorbing and transforming it for use in battle. The magical spirit was indeed full of spirituality.
His own magical spirit could also devour other creatures' magical spirits and plunder their Origin Power.
He felt that his magical spirit was now very powerful, but reason told him he was still far from where he could be.