Nilania, Witch of the Depths

Ward {2}
Other Merfolk you control have: "{t}: Add one
mana of any color. Spend this mana only to cast
a Merfolk, Kraken, Leviathan, Octopus, or
Serpent spell or to activate an ability of a Merfolk,
Kraken, Leviathan, Octopus, or Serpent."
Krakens, Leviathans, Octopuses, and Serpents
you control have Ward {2}.