I'll admit I was a bit surprised with the use of non original characters... but I actually think there is a bit of a gray area specifically due to the nature of NFTs. Publishers have traditionally turned a blind eye to commissions & original art sales of their intellectual property specifically because they're one offs and not mass produced. 1/1 NFTs are a pretty close proxy to that in the digital space. I wouldn't expect DC to sue him into oblivion if he sold the same illustration on Bristol board at a convention. Just another strange tech frontier that needs to establish new norms.