The memory-restoring formula known as the Memory Potion was originally created and concocted by the villlagers of the small town of Sun Do in the realm of Outworld. The potion made its appearance as a collectible item in the Konquest mode of Mortal Kombat: Deception.
A secret concoction of ingredients said to vastly improve short and long term memory.
While exploring Outworld, Shujinko came to the village of Sun Do, wherein he met a woman who was selling bottles of the potion. Shujinko purchased a bottle and subsequently brought it to the wandering fire elemental Blaze, who had no memory of why he was in Outworld due to the accursed magic of the Dragon King's holy men. When Blaze drank from the potion, all of his memories returned in an instant, including those of his originally intended quest.