Corozon's alchemical symbol - This is used it infuse the skull with Corozon's essence and thus speak to Corozon.

Corozon's alchemical symbol on the back of the skull.

This alchemical symbol is used to protect the copper nail from spiritual removal.  Copper is used because of it's purifying qualities.

Corozon needs to be encased in a copper cage for the users protection.  The less contact you have with the cage the better.  Corazon can be very influential.

The finished alchemical symbol for Corozon.