The Ismailis and their various branches

I am back to reading the book Secret Sects of Syria.

Chapter eleven is about Ismailis.

The chapter started by pointing out the Persian city of Khorassan as the hot-bed of the heresies, such as

Ravendi - doctrines of the transmigration of soul, and the successive incarnations of the Deity

Zendics - whose principle it was to believe nothing.

Hakim ibn-Hashem who was the under-secretary to the Governor of Khorassan, also known as "The Veiled Prophet" or al-Mokanna was active in the year 778 AD (timeline of the Abbasid caliphate).

He amassed a large army, influencing people by supposedly causing a number of miracles (moon to rise out of a well for several nights in succession). When he was besieged, he poisoned his army, his family and then committed suicide.

In the time of al-Mamoon (an Abassid caliph), another rebel and a heretic named Baber appeared in Iraq who went on to kill two hundred and fifty thousands Muslims in cold blood.

In the year 891 AD, the founder of the Karamatian (Qaramite) sect appeared. His name was Karmat.

I tried to find out more about Ravendi or Ibn al-Rawandi. According to the Wikipedia

He was an early skeptic of Islam and a critic of religion in general. In his early days he was a Mutazilite scholar, but after rejecting the Mutazilite doctrine he adhered to Shia Islam for a brief period and later became a freethinker who repudiated Islam and revealed religion.

He joined the Mu'tazili of Baghdad, and gained prominence among them. But then he became estranged from his fellow Mutazilites, and formed close alliances with Shia Muslims and then with non-Muslims (Manichaeans, Jews and perhaps also Christians). He then became a follower of the Manichaean heretic, Muhammad al Warraq in which he wrote several books that criticized revealed religion.

And I am not sure what or who zendic is. Under the wikipedia entry Zindiq, I get a few names.

Maybe Muhammad al-Waraq?

or Bashar ibn Burd?