Soul Crystal

This is the last of the four items needed to access the alchemical laboratory in Vega's Castle. It sits within Vega's Tower, accessible only by a glider flight from the clock tower. It is attached to a piece of machinery that comes out from the head of Vega's corpse. As its name implies, and related to how it is connected to the body of the alchemist, the soul of Vega himself must be entrapped within it.