badness vs evilness

badness and evilness both are nouns.

Word	Noun	Adjective	Verb	Adverb
badness	Yes	No	No	No
evilness	Yes	No	No	No

As nouns, evilness is a hyponym of badness; that is, evilness is a word with a more specific, narrower meaning than badness:

badness: that which is below standard or expectations as of ethics or decency
evilness: the quality of being morally wrong in principle or practice

Other hyponyms of badness include unworthiness, evil, undesirability, worse, unsoundness, liability, inadvisability.

badness (noun)	evilness (noun)
that which is below standard or expectations as of ethics or decency	the quality of being morally wrong in principle or practice
used of the degree of something undesirable e.g. pain or weather
an attribute of mischievous children