Greasy Fork is available in English.
FEH themed chess pieces.
< 脚本Chess.com Custom Pieces - Fire Emblem Heroes的反馈
Also, I almost cirtan that the problem is that the URL that you are trying to link to in your code don't work. Because A. My side does not see the image IE the download link. Or the link is dead if you're linking to a site.
IF Those images are stored on your computer when the link points me to them, I won't see them
It does not work. Tried on violent monkey and Stylus extensions. Kinda sad it would look fire ;).