Will to Live
You can't kill him; he has the tenacity of a cockroach.
It happened so suddenly; one moment, he was terrorizing some people who had made fun of his collar, and the next, he'd keeled over and fallen face first in the dust. One exceptionally kind-hearted Seventh Fonist ran to heal him, but it was too late. He had died instantly.
The Emperor demanded an explanation (he was his friend, after all), but there was no clear reason why. They examined him thoroughly; there was no disease, no injury. His heart had just stopped.
It wasn't until the report of the Necromancer's death at the exact same time that they fully understood.
Author's Notes: My definition of a drabble is 100 words. The part in italics at the top don't count.