I just watched someone upload the 2 images by sissypercy, again, and they got taken down again since they were previously uploaded and deleted by other people. Since it seems like Percy nuked all art utterly from this site, and I do not want to keep watching people do this, I think percy should probably be put on the DNP list. Too bad I'm not Percy.

It is the user's responsibility to make sure their uploads do not violate the Uploading Guidelines.
If they can't follow it, then they would keep getting their posts taken down until they learn their lesson.

Unless they have requested to be placed in the DNP list themselves, the artist can purposely spite reposters by issuing takedowns every now and then. Though I have not seen one with such time and commitment.
Regardless, third-parties cannot make requests for an artist to be added into the DNP list.

Of course, that doesn't stop them from informing the artist of its existence and recommending it to them.