All NFTs used for crafting are "burned." This means that they will be destroyed and no longer exist. For example, in order to craft a Silver Shadowy Super Coder, you must use 3 Commons. Once you claim the Silver Shadowy Super Coder, those 3 Commons will be destroyed.
Users can also burn NFTs earned during Season 2 to collect 75% of the NFT cost in Volts. This will be helpful if users are focused on earning a Gold or Trophy version of a specific NFT, and want to earn Volts to work towards that goal.