Board Thread:General Discussion/@comment-26167440-20151121005124/@comment-679780-20160121224933

Another theory is his hover shoes could actually be Darkness all along, but given Darkness became more of a traditional Extreme Gear later on I think that theory is nulled.

But my theory they could be powered by Life Energy could be a good guess. Unlike Badniks that draw off life energy of noral mortal creatures, Shadows shoes could syphon off from Shadows immortal life energy. Given the shoes are not exactly all-body robots, they only need some small ammount of energy at constant use only when he runs.

I believe Dr. Eggman entirely came up wit hthe designs of "Badniks", but it could be possible he found out about life-powered technology from his grandfather and weaponized it.