This is based on the game Minecraft, which included a weapon called the Diamond Sword.
Minecraft is a sandbox video game developed by Mojang Studios. Minecraft was created by Markus “Notch” Persson in the Java programming language and was released as a public alpha for personal computers in 2009 before officially releasing in November 2011, with Jens Bergensten taking over development around then. It has since been ported to various platforms and is the best-selling video game of all time, with 200 million copies sold across all platforms and 126 million monthly active users as of 2020.Wikipedia
Want to try playing Minecraft? Check out their website.