The Maa word engai carries three things at once: the divinity, the sky, and the rain. In a pastoral society on semi-arid grassland this is not a poetic conflation but a plain description of what matters, since the difference between a good year and a catastrophe is the rain, and the rain comes from the sky, and the sky is god.
Engai is one divinity understood through two aspects. Enkai Narok is the black god: black not as an ominous colour but as the colour of a sky loaded with rain and of grass after it has fallen. This is the benevolent aspect, the one that gives. Enkai Nanyokie is the red god, red being the colour of the dry season and the burnt earth, and this aspect is the angry one, which withholds rain, sends hunger and strikes with lightning. The colour scheme inverts the European convention entirely, and it inverts it for a reason a herder would find obvious.
The two are not rival gods and there is no myth of a conflict between them. They are the two things the same sky does. Which aspect is being addressed depends on what has happened and what is being asked, and a great deal of Maasai prayer is concerned with turning the red toward the black.
Engai's gender is not settled in the literature. The Maa noun takes the feminine prefix en-, and a number of accounts render Engai as female or as a mother; others use masculine forms; others hold that the question does not arise, since Engai is the sky rather than a person of any kind. The atlas records the disagreement rather than choosing, because the choice would assert something the sources do not.