it's mostly self trained, for example when I trained it to draw Rem from rezero, I had to write a very detailed prompt about Rem and made many generations of the same prompt then chose the most similar characters to her, then tagging these photos and giving them as data set to the AI, so when you write something like Rem from rezero it knows how Rem should look like, did I answer your question?
Sure, The AI is trained on photos which based on prompts, it's self trained, so to make it clear the AI was at first learning to draw by totally free anime photos then after it was good enough to draw by itself I started training it on its own photos (just the best of its work) which means you can use this AI tool to draw anything for personal or commercial purposes without any legal issues or someone asking you for credit, I can't credit the artwork of my AI so you don't have to credit it.
however I'd like if you will credit it to help spreading it as the project is new and it's doing great and it's getting many updates so please credit it by adding link to it
thank you for using ArtiManga, let me know if you have any question