I only wanted to add to Magister Rose's clear answers that group ritual usually serves more of a ceremonial function than one involving magic. The ceremonial function is often intended as much as self-reminder of Satanic principles as it is a declaration of intent in a social setting.

Both have a special power in their own way.

You never need do anything you do not wish to.
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Magister Nemo's Satanic Offerings:
DISCOVERING THE SATANIC GOD - The heart of Satanism.
THE SEVENTH TOWER OF SATAN - Ritual in virtual reality.
BENEATH THE SEVENTH TOWER OF SATAN - Deeper VR ritual.
THE FIRE FROM WITHIN - My book.