I'm Forever Washing Shadows is an achievement that requires the player to obtain the Divination XP lamp from Lord Amlodd by cleansing 15 of each blissful, truthful and manifest shadow cores. Each of these cores must be picked up by the player and then cleansed in the light rift, after killing the appropriate shadow creature. Do not use a legendary pet to pick up the cores, those cores will not count toward the 15 required. Cores obtained from motherlode or wythien count for this achievement.
Boosts can be used to receive this lamp and complete the achievement.
This achievement has a progress indicator in the achievement tab that displays whether the player has cleansed 15 of the same type of core.
When the player can claim the lamp and complete the achievement, they will receive the chat message "You've collected enough of a variety of shadow cores that Lord Amlodd would like to reward you".
Players may need to talk to Lord Amlodd before the achievement will complete, ask about "Amlodd Skills". If players have already picked up 15 of each core, before talking to Lord Amlodd, they may need to get 1 more core as a drop to force the achievement to complete.