insanely vs devilishly

insanely and devilishly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
insanely	No	No	No	Yes
devilishly	No	No	No	Yes

As adverbs, insanely and devilishly are synonyms defined as:

Other synonyms of insanely include deadly, deucedly, madly.

insanely (adverb)	devilishly (adverb)
in an insane manner	in a playfully devilish manner
(used as intensives) excessively	(used as intensives) excessively
	as a devil; in an evil manner