For Magi, spiritual energy was only used to create spell models—the model component of the spell. It was never meant to be used as the fuel for spells.
The only beings who could freely utilize spiritual energy were naturally creatures of the spirit world. However, it was nigh-impossible for the denizens of the material world to use spiritual energy so fluidly.
Now that Adam was seemingly out of mana, he had to do anything he could to survive. Therefore, as a last ditch attempt, he had to resort to using his spiritual energy.
Thanks to him possessing the white lotus, he was able to gain mastery over this energy in a very short amount of time.
The only other beings in the material world that could achieve this feat were naturally Magi who stood at the zenith of their respective schools of magic!
That is why Olin Barrett was so shocked to witness Adam wield spiritual energy so effortlessly. Furthermore, there was another reason.
