would it be possible to take it from an ai cg?
It could be a possibility, but it is not necessarily easier or better than the others.
A model would have to be trained for Atella’s images specifically and even with that the data set is limited, so there is no guarantee that it will work well or look as good as the original.
Besides I would only head on that direction if I had explicit permission from Atella, as the CGs are his work.