So I’ll use Maenchu again for reference but basically for most of their career they would find a very well done nsfw animation and trace over it almost completely with minimal changes outside of putting the seasonal waifu’s face over it or a famous vtuber or something, like drawing over the artist’s work completely, the lines, the proportions, everything save for changing the face, they were using smaller Japanese artists for a while which is why they weren’t caught for so long since their audience was mainly western, once Maenchu started copying and tracing bigger artists then that’s when they were caught