Find the missing term in the following: VMI, TKF, QGC, MEZ, ___?

Logic: Logic of the first alphabet of the given series of words (V, T, Q, M)  =  it follows a difference of (-2, -3, -4, -5) respectively. So the next term will be H . Logic of the Second alphabet of the given series of words (M, K, G, E)  =  it follows a difference of (-2, -4, -2, -4) respectively. So the next term will be A . Logic of the third alphabet of the given series of words (I, F, C, Z)  =  it follows a difference of (-3, -3, -3, -3) respectively. So the next term will be W .