Complex sentence: He claimed to be the prophetic fulfilment of Bábism, a 19th-century outgrowth of Shaykhism, and, in a broader sense claimed to be a messenger from God referring to the fulfilment of the eschatological expectations of Islam, Christianity, and other major religions.
Split into simpler sentences: He claimed to be the prophetic fulfilment of Bábism, a 19th-century outgrowth of Shaykhism, and, in a broader sense to be a Manifestation of God. He also claimed he was the fulfillment of the eschatological expectations of Islam, Christianity, and other major religions.