Holy Cow is a very solid card and can smooth out your draws while providing life swings that make the game difficult for opponents
Moving away from the flavour, we can totally see a spell such as Erase which exiles an enchantment (Gods = creature enchantment), or perhaps a weapon from Heliod - essentially an artifact with the same effect)
This was probably done because Duel Monsters was released before the first OCG set, Vol.1 , though it is not known why so few of the cards in the game have passwords, especially since the game credited at least nine individuals, but only six of them had passwords, and since the game includes 15 secret monsters, but only nine of them can be unlocked with a password
These cards are the primary going second tool for most decks, as they can negate crucial effects of opponent's cards in the middle of their combo
An opponent guesses whether the top card of your library is the chosen kind