Oh.  My.  God.

When I talk about why Gravekeeper's is a good theme, I mention one thing 90% of the time; support cards that don't require convoluted combos to be awesome.  GK is such an awesome theme that certain cards leak from GK to other decks…  Necrovalley was featured in Scientist OTK's, GK Spy is featured in decks to this date by itself, and we can even catch the occasional GK Spear Soldier.  GK Watcher was used as a (bad) counter to the Empty Cookie Jar FTK Mill deck.

This card is the GK Spy of Dark World.  Essentially, it gives you a chainable card that special summons a monster with no strings attached.  Activate it at the end of your opponent's turn to give yourself a surprise beatstick, or during your turn for an instant 2300, or during their Battle Phase to END the Battle Phase.  Oh, what happens if they MST it, though?  Jack all happens, friend.  You don't need this to remain on the field, unlike Premature Burial and Call of the Haunted.  You get a free 2300 if they activate removal on this card.

Impressed?  Same here. 

This is an arguable staple in any combo-oriented Dark World deck.  At least play one.  It's easy to get.

Dark World:  4.3/5
General:  Crap.