Just a translation phenomena.. No damage and Zero damage look similar and in most cases would mean the same, however this is a case where it makes a difference.
The Card has been errata'd:
Waboku
(Starter Decks: Yugi, Joey, Pegasus, Yugi Evolution)
Make all Battle Damage inflicted by monsters on your
opponent's side of the field 0 during this turn.
Yet still puts the number Zero in. Zeros are confusing and they remain beyond the understanding of folks at UDE. Think of Zero as a word--not a number-- a synonym for None.