If for some reason you can't win the game (because your opponent has cast Angel's Grace this turn, for example), you won't lose for having tried to draw a card from a library with no cards in it
Frankly, I've never ultimate-d him, because I'd always rather kill something or draw cards and drain life from various effects, but it's nice to know that you have a big effect that could win the game in one hit
For completeness sake: The player cant choose an option thats illegal or impossible , with the exception that having a library with no cards in it doesnt make drawing a card an impossible action (see rule 120.3)
Lower Japanese retail prices offset some of it, and shipping in batches spreads the international postage across more cards
it's only 4 mana to cast, and the second ability on Kykar is why I added it over Ovika
It can be used late game to great effect