Inductive Rractance: Definition
the opposition of inductance to alternating current, equal to the product of the angular frequency of the current times the self-inductance. Symbol: XL
Inductive Rractance is the "Generation" of E.M.F in the opposing direction in the same coil, this increases the "Resistance" of the Flow of Current in the Coil which is commonly known as B.E.M.F or Back EMF.
As the "Generation" of B.E.M.F increases, the Coil becomes more Inductive, or becomes more "Resistive" to the Change in Current.
Inversely, the Coil is also susceptible to any and all external influences. If the Secondary Coils are "Generating" more E.M.F than is being supplied, and is at the right phase, then the Input Coil's Inductive Reactance will change, and can push the Phase Shift back.
Inductance changes with the Magnetic Field. I have shown a really important experiment here. This shows that with an increasing magnetic Field, the Inductance decreases.
This is how the Paraformer works. The Change of Inductance over Time creates an E.M.F.
By making the Input appear highly Inductive at the right time, then the Change in the Output's Magnetic Field sends power back through the Input Coil.