Which letter cluster will replace the question mark (?) to complete the given series?

ZXVY, DXZY, ?, LXHY, PXLY

HXDY

Explanation:

ZXVY, DXZY, ?, LXHY, PXLY

The logic followed here is :

Z → (-1) → D → (-1) → H → (-1) → L → (-1) → P

X → (+2) → X → (+2) → X → (+2) → X → (+2) → X

V → (-3) → Z → (-3) → D → (-3) → H → (-3) → L

Y → (-3) → Y → (-3) → Y → (-3) → Y → (-3) → Y

So, the letter-cluster that replaces the (?) to complete the series is "HXDY"