[Phantasm]

One thing with Dr. Strange is that most of his high-power spells are not fueled by him or even ambient mana, but by entreating god-like entities for power: the Crimson Bands of Cytorrak, the Winds of Watoomb, Flames of the Faltine, etc. all call upon the entity named to give him energy and/or cast the spell itself with him directing it.

Even his bread and butter spells (f'rex, eldricht blast, eldricht shield) draw upon ambient magical energies rather than his own. Still not sure how to separate eco-centric and exo-centric magic from the "powered by personal energies" ego-centric magic (which is limited to stuff like telepathy, Jedi mind tricks, and astral projection).