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.
What is it (Top) The muse is the manifestation in the physical world of what we need to experience to manifest what we desires to create. The muse is the physical manifestation that supplies, or rather is the occasion for, the passion to act in the world. In this regard, the muse acts as the external sources of our creative life energy.