The Mystic Falls Codex

Captured by the Augustine society and held for seventy years, bled and cut open as research alongside Damon Salvatore. Damon escaped in 1958 and left him in a burning building. Enzo survived, stayed in captivity for another half-century, and came out with a plan for exactly what he would say.

He becomes Bonnie Bennett's one real love, is enslaved by Sybil, and is killed by Stefan in front of Bonnie — which nearly costs the world a Bennett witch's restraint.