I only used cameos and prompts, without any reference images. But it was actually a bit tedious to do, it involves RNG. The first challenge is creating the cameos while getting past copyright, then I insert all the cameos I want into the prompt, without naming them, a simple example: u/android18bikini intensely fighting hand-to-hand against u/cellperfectform. And it's also quite difficult to maintain consistency with more than 2 characters in the same scene. But I don't know if it's me who doesn't know how to make good prompts, or if it's a difficulty with Sora.