devilish vs devilishly

devilish is an adjective but devilishly is not an adjective.

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

As adverbs, devilish and devilishly are synonyms defined as:

devilish (adjective)	devilishly (adjective)
showing the cunning or ingenuity or wickedness typical of a devil
playful in an appealingly bold way

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