brutal vs unrelenting

brutal and unrelenting both are adjectives.

Word	Noun	Adjective	Verb	Adverb
brutal	No	Yes	No	No
unrelenting	No	Yes	No	No

As adjectives, brutal and unrelenting are synonyms defined as:

brutal (adjective)	unrelenting (adjective)
disagreeably direct and precise	never-ceasing
resembling a beast; showing lack of human sensibility	not to be placated or appeased or moved by entreaty
punishingly harsh	punishingly harsh
(of persons or their actions) able or disposed to inflict pain or suffering