Complex sentence: These prophecies are taken together with those of the coming of the Mahdi and both the terms "Jesus Son of Mary" and "Mahdi" (as used in Islamic apocalyptic literature) understood synonymously as two titles for one and the same person.
Split into simpler sentences: These prophecies are also taken together with those of the coming of the Mahdi. Both the terms "Jesus Son of Mary" and "Mahdi" (as used in Islamic apocalyptic literature) are understood synonymously as two titles for the same person.