Wait, it's just an error?

Errors are easy to kill! You quickly assume a fighting stance and execute a perfect finishing move. The error is slain the moment your mighty fist strikes, and the force of you attack sends its lifeless carcass at least 20 feet. Victory!

You take twenty to search the error's remains for gold and items. You find about 20 gold, as well as an unusual blue sparkling sword. Weird, but probably valuable! Should you try to unlock its mystical secrets, or just sell it?