heroic vs impressive

heroic is a noun but impressive is not a noun.

Word	Noun	Adjective	Verb	Adverb
heroic	Yes	Yes	No	No
impressive	No	Yes	No	No

heroic (noun)	impressive (noun)
a verse form suited to the treatment of heroic or elevated themes; dactylic hexameter or iambic pentameter

heroic (adjective)	impressive (adjective)
relating to or characteristic of heroes of antiquity	making a strong or vivid impression
having or displaying qualities appropriate for heroes	producing a strong effect
showing extreme courage; especially of actions courageously undertaken in desperation as a last resort
of behavior that is impressive and ambitious in scale or scope
very imposing or impressive; surpassing the ordinary (especially in size or scale)