A Monument to All Your Sins

A Monument to All Your Sins is a Campaign Achievement in Halo: Reach and Halo: The Master Chief Collection. This achievement is awarded when a player completes every campaign mission in Halo: Reach on Legendary solo. It is represented by a Legendary symbol with a human skull rather than the traditional Sangheili skull.

Trivia

 * The achievement's name is derived from a quote from the Gravemind: "I? I am a monument to all your sins."  This line is also said by Cortana while under the influence of the Gravemind.
 * This achievement has somewhat the same icon as the "Hired Gun" achievement from Halo 2 Vista.
 * Completing the Campaign on Legendary will also award the "Gods Must Be Strong" Achievement, which does allow for co-operative play.