When its flipped up, you destroy the top 5 cards from your opponents deck
Its ability looks pretty insignificant at first but combined with certain cards, it can help you produce infinite mana, buff your creatures with a gazillion counters and draw at the same time, or even have infinite turns
"The MODO Fiasco: Corporate Hubris and Magic Online"
GR Gold Rare Graff, Malebranche of the Burning Abyss X DARK Level 3 [ FiendEffect ] ATK 1000 DEF 1500 If you control a monster that is not a "Burning Abyss" monster, destroy this card
Entreat the Angels, Starnheim Unleashed, Finale of Glory, and Decree of Justice all reward you handsomely for spending a lot of mana on them
Lower numbers are generally more exciting, but if you open the biggest number in a run (like a 500/500), thats usually worth more than a middling number, too