The section on Ephemerals in the Demon:The Descent manual and Chronicles of Darkness manual describes Manifestation powers for Ephemerals and even gives a map of how they interact. However I don't see any example of opponents that actually use the mechanics of Fettering and Reaching and Anchoring etc. Even the book on Night Horrors doesn't seem to have any opponents that use them. It's as if you read the rules for chess and the book described in great detail how magic affects how the pieces interact but no chess game you've seen or heard about uses them.
It might be that these powers are central to other splats such as Geist and Werewolf. If so, can you point to a particular manual that gives a good example of their use?