In Sonic X, the Chaos Emeralds echoed their role in the games as objects that were sought after by all parties. However, the series also introduced a new concept: Chaos Emeralds reacting to each other. Whenever Chaos Emeralds are brought together without being given time to adapt to each other's presence, they release immense quantities of energy. (This concept however disappeared after the first half of Series 1, as in the second half and Series 2, the Chaos Emeralds are brought together with no ill effects) Also, all seven being in one place results in them releasing energy that push them away from each-other. This is likely the anime's way of creating an explanation as to why the Chaos Emeralds end up scattering, as opposed to when in the video games they just seem to mysteriously scatter for no reason. While that's generally why they scatter in Sonic X, at the start of the second series Sonic actually did have seven emeralds, and he scattered them across the galaxy to keep Dark Oak from taking them from him (Dark Oak was too powerful for Sonic to defeat even when he was in his Super Form). Later in the same season, the Emeralds are scattered again by a gravity warp created during a battle between Super Sonic and Super Shadow. In the Season 2 episode A Robot Rebels, Knuckles has a vision of the past showing Tikal at the Emerald Shrine. The 7 Chaos Emeralds are there, but quite different than the modern ones. They appear much larger, are shaped differently.