Bombinomicon: Okay, twist ending guys. Here comes the big twist! I'm an angel, and we're in Heaven! This was a test all along! No, I'm pulling your leg, there is no Heaven. There is Hell in every direction.
Originally, the Short Circuit was designed more as a minigun like weapon that opened up from the Engineer's glove. However, Valve decided to they wanted a less powerful electric based weapon, so the current design is what it was changed to.