Question about the goddess, Isis?

Isis is more for working in the confines of Holy Magick. For Shadow workings, Sekhmet works great. Lion-headed goddess of war and destruction. Be careful with destruction deties, such as Sekhmet, Set(god of storms, chaos and the desert), Typhon, Kali Ma, Satan, etc, as they tend to be very volatile in nature. I'd suggest using a Triangle of the Art, with the sacred names you prefer to use.