This achievement is one of final achievements of the game and is only available if you save Algernon Drake at the end of Chapter 10, unlocking:
After destroying the three glyphs and returning to Algernon Drake the final time, the Shambler will be dragged into the painting via interacting with the painting. During this time, it will grab onto Drake's leg -- simply press
to save Drake before he too enters the painting.
If you save him, Drake will be at the final summoning ritual in Chapter 14 with the R'lyen Key. This will allow you to select [Perform the Counter Ritual] as the last option of the game. Achievement unlocked.
(NOTE: Once you finish the game, you can reload your save to get any other ending available as part of the last option.)