Adela and Aziz are the primary actors in the central drama of A Passage to India, and they are antagonists to each other. But the novel isn't weighted in favor of one over the other. Instead, it attempts to give a candid account of both characters who seem to be carried away by forces beyond their control.
With Adela, Aziz is the other primary actor in A Passage to India. As we mentioned in our discussion of Adela above, they are antagonists to each other, and they take turns being protagonists as the narrator switches perspectives.