When Gisa and Geralf enters the battlefield, put the top four cards of your library into your graveyard.
During each of your turns, you may cast a Zombie creature card from your graveyard.
7/13/2016 You must follow the normal timing permissions and restrictions of the Zombie card you cast from your graveyard.
7/13/2016 You must pay the costs to cast that Zombie card. If it has an alternative cost, you may cast it for that cost instead.
7/13/2016 Once you begin to cast the Zombie card, losing control of Gisa and Geralf won’t affect the spell.
7/13/2016 If you cast one Zombie creature card from your graveyard and then have a new Gisa and Geralf come under your control in the same turn, you may cast another Zombie creature card from your graveyard that turn.
7/13/2016 If a Zombie card is put into your graveyard during your main phase and the stack is empty, you have a chance to cast it before any player may attempt to remove that card from your graveyard.
7/13/2016 If multiple effects allow you to cast a Zombie creature card from your graveyard, such as those of Gisa and Geralf and Karador, Ghost Chieftain, you must announce which permission you’re using as you begin to cast the spell.
7/13/2016 Even though the cards portray the same characters, Gisa and Geralf has a different name than Ghoulcaller Gisa and Stitcher Geralf. Controlling Gisa and Geralf along with Ghoulcaller Gisa or Stitcher Geralf won’t invoke the “legend rule.”