Dark Gems

These crystals are infused with the Convexity Element and corrupt all things surrounding them. In A Hero's Tail, this is Red's destructive means for getting his revenge on The Order of Dragon Elders and his attempted takeover of the Dragon Realms.

Uses
Dark Gems are initially found in a raw crystal state and are then encarnated with the Convexity Element. To unleash its effects, it must be planted into an subject such as the ground or another being in which it begins to drain and corrupts its life force. If one wished to control it without being exposed to the Convexity Element, they need to create a rely device such as Red's Sceptor.

There are also useful effects to using a Dark Gem such as eroding obstructive terrain, force fields, safeguards against thieves, and enhanced Dragon Kata abilities.