When a user posts a pixiv media link, catch the message. Use the pixivpy library to query their API for metadata. Reply to the OP with a message embed various relevant metadata such as linked title, author, likes, favorites, number of posts in the set (if applicable), tags in English, media thumbnail, and truncated description.
Do not post the embed to the channel the link was submitted to if the piece has tags that match a "do not post list." Instead, route the embed to a configurable moderator channel, omitting the thumbnail, mentioning a configurable staff-only role, and highlighting the tags in violation.