Devastating
From Halopedia, the Halo wiki
Devastating
Devastating is an achievement in Halo: The Master Chief Collection. It is unlocked by completing the Halo 3 campaign on Legendary in under 3 hours.
The 3 hour time limit is calculated as the sum of the player's best times on each level on Legendary; players can view their best times on their Halo Waypoint service record. As a guide, players should roughly aim for the par times as they total 2:40.
Trivia
The achievement is named for Halo speedrunner DarkDEVASTAT10N.
