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.
Definition: (v.) to think about or ponder something deeply; (n.) the source of inspiration for an artist. Synonyms: (v.) consider, ponder, think, dwell, meditate, contemplate, mull, reflect, (n.) inspiration. Antonyms: (v.) ignore, forget, divert. Tips: The Muses of Greek mythology were nine goddesses who presided over and protected the arts and sciences and who were said to inspire poets and artists. You may still hear people today refer to someone as their muse, because they inspired them and galvanized them to succeed.