I believe that a change to this card is already in the works. I recall looking at a preview and noting that it was being changed in a way that resembled its original version.
Originally, this card damaged both players for 20-5N where N was the #Undead in each player's own hand. This meant that playing it without the optimal 5 Undead would damage you while playing it and that any Undead the opponent had in hand would reduce the damage taken. It also meant that a rush deck could use it as a finisher without having any Undead in hand at all.
If I recall correctly, the proposed change did still require having Undead in hand to deal the damage. EDIT: I found the
topic in question, though the link to see the cards seems to be down.