Can Blight/Event/Fear Card effects add or move pieces to locations that aren't lands if those locations are in play (e.g., adding pieces to the Ocean if Ocean's Hungry Grasp is in play)?

Can Blight/Event/Fear Card effects add or move pieces to locations that aren't lands if those locations are in play (e.g., adding pieces to the Ocean if Ocean's Hungry Grasp is in play)?

Generally no, pieces can only be added to a non-land location if explicitly allowed by whatever puts that location into play or temporarily lets that location be treated as a land. So, for example, an Event can add Blight to an Ocean if Ocean's Hungry Grasp has Presence on that board or the Kingdom of Scotland is the Adversary, since both of those let the Ocean be a land for the purpose of Blight. However, an Event can't add or move an Invader into an Ocean, even if an Ocean otherwise met the qualifications on adding that Invader, since the "Ocean in Play" special rule doesn't make the Ocean a land for Events in general.
However, Ocean's Hungry Grasp can add or move Presence to an Ocean via a Blight/Event/Fear Card despite that Ocean not being a land for such effects, since "Ocean in Play" lets Ocean's Hungry Grasp add and move Presence into Oceans. So for example, Ocean's Hungry Grasp:
  • Can move Presence into an Ocean on a board where they have Presence during the "Clever Cooperation" Event or if they choose to leave behind that which restrains them during the "The Struggles of Growth" Event; and
  • Can add destroyed Presence to an Ocean with their Presence when choosing to focus their will towards wholeness during the "Dissolution Threatens" Event, or as part of flipping the "Burn Brightest Before the End" or "Unnatural Proliferation" Blighted Island Cards.
On the other hand, even if another Spirit legally gets Presence into such an Ocean, they can't take advantage of these Event and Blight Cards, since they have no ability to bypass the Ocean not being a land for those Actions. (And similarly, these Event and Blight Cards can't add Presence to The Endless Dark, even if a Spirit has Presence there, since no Spirit is granted the ability to do so.)