The main focus of the composition is a large Gothic castle located in the center of the back. The castle should be detailed and atmospheric, but not overloaded — it should be the main element of the entire composition.
Above and below the castle, I want reworked sun and moon designs inspired by Soul Eater, but executed in a Gothic fantasy style, so they fit better into the overall composition rather than looking like direct elements from anime.
I also want Mega Rayquaza (Pokémon) to be integrated into the composition, but more in the background rather than as a dominant element. It should look like part of a Gothic world and not stand out too much.
The castle can be complemented with decorative elements such as dark ivy, roses, or other Gothic details if they look good in the composition. If not, they can be omitted.
Overall, the goal is a cohesive Gothic fantasy composition for the entire back, where all elements look like one scene rather than separate objects.
I hope these sketches help in some way.