What is the artwork expectation for a commitment like this? One complete illustration? Ten? However much is appropriate to the fic?

At least one complete colored illustration or three pencil only illustrations. They must be on a clean sheet however, so no notebook paper. Beyond that, I'm not an artist so I have trouble drawing the line. One quality picture would be ideal though. :)

Are those who had not been involved at the start of this round of hardmode welcome to participate?

Of course! There are no sign-ups needed to jump in as an artist at this point! \o/