unmerciful vs mortal

unmerciful is not a noun while mortal is a noun.

Word	Noun	Adjective	Verb	Adverb
unmerciful	No	Yes	No	No
mortal	Yes	Yes	No	No

unmerciful (noun)	mortal (noun)
	a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential

unmerciful (adjective)	mortal (adjective)
having or showing no mercy	subject to death
	unrelenting and deadly
	involving loss of divine grace or spiritual death
	causing or capable of causing death