Look, its nice that you like my best friends artwork but this is really hurtful and sad, id appreciate if you owe up to your mistake and delete everything. She's worked so hard to make her style for years, I experienced it myself and she spent so much hard work on it, please do not steal her work.
You can create your own art through practice, stealing someone else's really isn't worth it, you will get caught time and time after again.
If you wish to apologise to the artist I can pass on the message but please for now on practice yourself, learn your own style and most importantly post your own art, I hope mine and others actions were not too rough but enough to teach you a lesson, I'm trying to be as understanding as I can as we are all human and we make mistakes.
Edit: If you fail to delete the work at the very least soon I will not hesitate to report you for stealing another artists work which can lead to being banned permanently from deviant art, I have not yet as I believe in second chances.
If you wish to talk to me or ask about this situation or some sort of advice I am open to a discussion.
Do not take this as people being mean, harassing or bullying you, I am stating what you have done wrong and warn you to not do this again as some REALLY may not take this situation lightly. Hope you have a good day and make right choices in the future.