[nothingclever]

1. This is not stealing, stealing requires theft, or an illegal seizure of property. One can do this because the images provided on deviant art are public, and provided to the public, thus they can be legally acquired without the permission of the creator.
2. This is using licensed characters, non commercial use of licensed characters are considered public domain.
3. Consent of the original artist is legal, so as long as that person does not claim to be the original authenticator of the artwork. They do not need to necessarily have permission to re post, but it is considered good form. If they say the art is their creation, now theft has taken place, identity theft.

So, nothing wrong here yet.