BDFH, CBID, DZLZ, EXOV, ------------------------
SRUF
FVQR
FVRR
FURR
FVRS
BDFH, CBID, DZLZ, EXOV, ------------------------
In this series, first character follows the pattern of +1, second character follows the pattern of - 2 and third character follows the pattern of +3 and fourth character follows the pattern of -4.
So, at the end, E+1=F, X-2=V, O+3=R, V-4=R