Fanworks and Usage of Already Existing Sprites/Music

[Nazofox2501]

Nazo here.

One of my just-for-fun ideas is turning my "Yugioh! Abridged" fanfiction into a visual novel. Since I'm completely new to the whole visual novel creation process, I had a few legal questions in regard to the topic:

1. Are fanworks of an already existing medium allowed on Ren'Py?
2. I have no tools or talent to make my own sprites, so I thought about using sprites from here https://www.spriters-resource.com/genre/visual_novel/ to use. Is that allowed?
3. Ditto for music that can be found on YouTube and converted to mp3 format.

If any of these are answered with a "no", I'd like to know now before I devote myself to the idea. Also, if the sprite website and YouTube videos of music can't be used, what alternative sites or sources can I use?

[SundownKid]

Yes, they are allowed by Renpy. And in fact your fan game would likely be considered legal overall because it falls under the 'fair use: parody' exemption of US Copyright law.

However that said, straight up using sprites and music from other games willy nilly would likely be copyright infringement since it's unrelated to what you are parodying. However, it's unlikely that anyone will go after a small fan project unless the sprites you are using are from indie games themselves.