Memory Fragments in Rogue Legacy 2 are small blue orbs you will come across in your travels throughout the roguelite’s deadly castle.
When you first interact with a Memory Fragment, your character can hear a thousand whispers, but can’t make out a voice. This is because a special item is required to read Memory Fragments.
You need to read Memory Fragments in Rogue Legacy 2 in order to progress with the story, so finding the item needed to translate ‘a thousand whispers’ is essential.