Does a monarch butterfly symbolize devil worship?

No it does not. There are people that associate it with the MKULTRA MONARCH Slave program, and it is supposed that the bearers of this tattoes are alleged slaves under this program. Butterflies have many meanings depending the color in different cultures. Usually the wide spread belief is that butterflies represent regeneration, transition and new life. Some other cultures may associate it with the soul of the departed, often times associated with visiting souls of relatives, and different Omens and Good Signs depending on the color and where it is you see them and how. Ultimately the butterfly itself doesn't represent anything else than a butterfly.