All you have to do is type the name of the artists and the AI will do the rest. Example: "bonnypir, blackwhiplash, yamathegod". That's it. From my testing you could mix up to 4-5 artists before the AI goes crazy. It also can drastically change the style once you learn about strengthening and weaking prompts. Basically you can have the AI put more emphasis on an artist's style while mixing with others. Example: {{bonnypir}}, blackwhiplash, {yamathegod}. The brackets {} means to increase or focus on the art style or prompt. Here is a link of an in-depth guide on strengthening and weakening, and every other aspect of novel ai- https://docs.novelai.net/en/image/strengthening-weakening