With future perfect (F2) you jump to a point in the future, turn round and say some action is finished then. Actually a complicated thing and cumbersome and in most cases you can express the same idea much simpler without using F2. This tense existed in Latin and it was imitated by writers.
In current English usage, muse can refer in general to a person who inspires an artist, writer, or musician.
The definition of a muse is a spirit or source that inspires an artist. An example of muse is someone having a thought about the origin of life. An example of muse is the character Kira from the movie Xanadu. Muse is defined as to have deep thoughts or to meditate.