Part 3/9:
In “The Return of the King,” there is a scene where Gandalf conjures a spell that repels Nazgûl, demonstrating that offensive magic is within the bounds of possibility. Despite this capability, characters like Gandalf, Morgoth, and Sauron do not rely on overwhelming displays of magical prowess for several significant reasons.
The Limitations Imposed by Corruption
Morgoth and Sauron, having rebelled against Eru Ilúvatar (God), faced a critical consequence for their rebellion; their connection to their creator was severed, resulting in a finite supply of energy. Each spell they cast consumed a portion of their dwindling power. For instance, Saruman, once the most powerful of the Maiar, expended so much energy that he was left nearly powerless, enabling his defeat at the hands of hobbits.