important vs most-valuable

important and most-valuable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
important	No	Yes	No	No
most-valuable	No	Yes	No	No

important (adjective)	most-valuable (adjective)
of great significance or value	designating the player judged to be the most important to the sport
of extreme importance; vital to the resolution of a crisis
important in effect or meaning
having or suggesting a consciousness of high position
having authority or ascendancy or influence