Q: Which Light fills Malchut - is it one Light or five Lights?
A: Malchut (the soul) is divided in five parts (from fine to coarse): Keter, Hochma, Bina, Zeir Anpin, and Malchut, in ascending order of the power of the will to receive. The strongest desire takes the last part – the Malchut of Malchut. These desires receive with five pleasures – Lights that fill them respectively: Yechida, Haya, Neshama, Ruach, Nefesh.
Malchut is divided into five parts in a reversed order, from coarse to fine: still, vegetative and animate, speaking and Godly. Hence, the strongest will to receive (the Malchut of Malchut) is called still, and is filled by the dimmest Light, in the level of still, the Light of Nefesh(Nefesh of Nefesh).
In the spiritual worlds is a law called “the opposite value of Lights and vessels”: the coarser the desire that aspires to receive greater pleasures, the more Light it extends. But the Light goes not into the coarse desire, but into the finest one, into the desire to give without any reward, because the Light and the finest desire to give are in equivalence of form.
It is also customary to say, “The Lights enter the Partzuf gradually.” But any change in the Light means a change in the vessel, and therefore, in the entire Partzuf. Everything is new each time, all five Sefirot and all five Lights.