InQuest

When Cortexic Jellyfish attacks, it does not untap during its controller's next untap step.
: Untap Cortexic Jellyfish.
, : Put a -0/-1 counter on target creature without flying. At the beginning of each of that creature's controller's upkeeps, put a -0/-1 counter on that creature.

If Elminster is untapped and does not have summoning sickness, you may tap Elminster as you cast a spell from your hand. If you do, then you control an opponent of your choice while casting that spell. While you control that player in this way, that player can only activate mana abilities of lands they control, and only if that mana is sufficient to pay the cost of that spell or if that mana is spent on the cost of other mana abilities that are played in this way. You can spend that mana to cast that spell, but you cannot spend any other mana on the cost of that spell.

Flying
: Shivan Drake gets -1/-0 until end of turn. Put a -0/-1 counter on target creature. This ability can only be used if Shivan Drake is attacking and only if its power is greater than zero. This ability cannot be used if another instance of this ability is already in the stack.

Islandwalk
The Black Orchid cannot attack unless defending player controls an Island.
When you control no Islands, sacrifice The Black Orchid.
When The Black Orchid leaves the battlefield, exile all Zombies and Skeletons you control.
, : Search your library for a Zombie or Skeleton card and put it into the battlefield, and then shuffle.