Divinity: Original Sin Enhanced Edition

In the Haunted Forest, near a huge tree, we meet a mute Immaculate One, who steals the voices of animals. After killing him, we learn that Wolgraff can get his voice back. To do this, you need to combine the sound tree (remains after the death of the sectarian) and the bottle with voices (it is located in the Temple of the Dead). Mix and give the potion to Wolgraff. (It works even if you never took him with you as a travel companion, just take the potion to him in the hall at the End of Times, where all the NPCs you meet in the game are waiting for you)

My Wolgraff is buggy. I brought the potion to him at the End of Times, and there was only his armor standing there and it was impossible to talk. The solution is the following - carry the potion until the end of the game and at the very end, in the Academy, he walks around the room with other heroes. That's where I got this achievement