The section on ephemera in the Demon: the descent manual and Chronicles of Darkness manual describes the ephemeral manifestation powers and even gives a map of their interactions. However, I do not see any examples of opponents who actually use the mechanisms of Fettering and Reaching and Anchoring etc. Even the book on Night Horrors does not seem to have any opponents using them. It's like you're reading the rules for chess and the book describes in detail how magic affects the way the pieces interact, but no game of chess you've seen or heard of uses them.
It may be that these powers occupy a central place in other areas such as Geist and Werewolf. If so, can you name a particular manual that gives a good example of their use?