scenario vs scenarist

scenario and scenarist both are nouns.

Word	Noun	Adjective	Verb	Adverb
scenario	Yes	No	No	No
scenarist	Yes	No	No	No

scenario (noun)	scenarist (noun)
an outline or synopsis of a play (or, by extension, of a literary work)	a writer of screenplays
a postulated sequence of possible events
a setting for a work of art or literature