Here is the village idiot. Devas are various Gods, lesser Gods, and Devis are various Goddesses. Saguna Brahman can be seen in many forms and not just Brahma. It is Vishnu and Shiva too as well as many other Gods. Nirguna Brahman is just that, does not act, assumes no form. There are no angels and archangels in hinduism (Brahman's errand boys or girls, Wikipedia mentions a female angel also).