From looking at your other images, I assume you used img2img, and some image editor as well? This is pretty nice.
Ah yeah, I just use Krita for merging images. The key things I recommend are: comfyui-impact-pack's maskdetailer, comfyui-prompt-control, and merging your own models w/ ModelMergeSimple (part of Comfy-Core) to get the art style that you really want.