Orithor, the Ancient Deep

{1}{u}, Discard Orithor: Return target nonland permanent to its owner's hand. Mill three cards.

Escape—{4}{u}{u}, Exile six other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

When Orithor enters, if it escaped, return up to
one target permanent to its owner's hand for each
Kraken, Leviathan, Octopus, or Serpent card
exiled to escape it.