A Monument to All Your Sins (capitalized A Monument To All Your Sins in Halo: The Master Chief Collection) is a CampaignAchievement 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 humanskull rather than the traditional Sangheili skull.[1]
The achievement's name is derived from a quote from the Gravemind: "I? I am a monument to all your sins." [2] This line is also said by Cortana while under the influence of the Gravemind.[3]