|The title of this article is conjectural.|
The Empathy Spell was a spell cast by Eragon, causing his nemesis Galbatorix to feel every emotion felt by the people around him since he had been born. The spell was augmented by the power of the dragons, increasing its power and effects. Eragon's original intention was to simply make Galbatorix understand the nature of his actions and the feelings that he engendered in others, but the dragons' Magic did more than make Galbatorix simply understand. It made him feel every thread of fear, pain, anguish, and hatred that everyone throughout time felt because of him.
The spell required the assistance of nearly two hundred Eldunarí and was considered to be one of the greatest pieces of magic ever wrought. Due to the communicative, not combative, nature of the spell, it was able to bypass the remaining wards Galbatorix had left after Murtagh stripped him of his more prominent ones.
The spell did not directly cause Galbatorix's death but confused and hurt him severely. Due to the pain it caused him, Eragon was able to stab him. However, the stomach wound that he was given was likely not fatal. Galbatorix, however, was no longer able to properly fight, nor maintain his concentration to give resistance. He begged Eragon several times to end the magic, but when Eragon would not, he chose release through a suicidal spell that would have also destroyed Eragon and his allies, had Eragon not cast magic without the use of the Ancient Language to protect them.