Regarding Copyright

Honestly, it's best not to touch anything ambiguous 🫠 While it seems like it's in a gray area and okay as 'secondary creation,' for VTubers, things that damage the 'liver's image' are often prohibited by the VTuber's own creation rules. It's fine as long as it's at the level of reusing 'character settings,' but excessively modifying it to your liking will cause problems. Also, since zeta has scenes that involve R15 and R18 content, sharing talk content on social media can lead to a strange image and cause issues. Basically, I think it's safe to assume it's okay as long as you follow the 'secondary creation' rules. If you read this far and still conclude 'I don't really know' after researching yourself, please don't touch it. If it becomes a problem and reaches the original creators, there's a possibility that creation itself could be banned.