Echo

Echoes are a magical copy of a slain Nightmare Creature. They are capable of limited autonomy but do not possess a soul, and thus are not alive. Just like Memories, they are created from Soul Essence and assume physical form only when summoned. They can be destroyed permanently and take time to heal just like Memories.^[1]

Since echoes were mere replicas of the creatures that had left them behind. They were molded in their image and never changed, always remaining the same as the originals at the moment of their deaths.^[2]