Surtur, empowered by the Eternal Flame in Thor: Ragnarok, kills Hela by destroying Asgard.
Hela, the Asgardian goddess of death, posed a significant threat to the realm and the universe. While Thor, Loki, and the other Asgardians fought valiantly, they were unable to defeat her directly. Hela's immense power and control over the dead made her seemingly invincible.
However, Thor realized that the only way to truly defeat Hela was to fulfill Ragnarok – the prophesied destruction of Asgard. To achieve this, Loki resurrected Surtur by placing the Eternal Flame in his crown. Surtur, now in his colossal form, unleashed his fiery power, obliterating Asgard and, consequently, killing Hela in the process. Her power was intrinsically tied to Asgard, and its destruction led to her demise. It wasn't a direct one-on-one fight, but rather a strategic maneuver that leveraged Surtur's power to eliminate the threat she posed.
