And the lord of a lot generally indicates the outcome of an issue. Hence Rhetorius’ delineation of Basis.
Eros and Necessity are formed from Fortune and Spirit. Such derivative lots make the meaning of Fortune and Spirit more specific. I see no reason why we cannot form many more derivative lots along the same pattern. For instance, there are two generally noxious lots formed from the two malefics, and both are reversing lots. One is counted from Saturn to Mars by day and the reverse by night; the other is counted from Mars to Saturn by day, and the reverse by night. These two lots will always be symmetrical to each other across the Asc/Dsc axis in the same manner as Fortune and Spirit, and I maintain that they will have complementary meanings in the same way that Fortune and Spirit do.