A purple butterfly.

( He puts a hand to his chin in thought. Then its the same as his own memory - must be a magical signature, of sorts. )

Then we must find it and use it to break the enchantment. When next you see it, grasp it and listen for a voice outside of this memory. You will need to focus on that completely - not the pain, the sound, or your companion. Block out all else.

( Then, as happened with his own memory, the re-shift in focus to those 'judging' this should allow this illusion to dissipate. One could hope. )