The Center supplies the entire castle with the necessary energy, and it is also used to recharge the power stones. The stream is apparently generated by a gigantic power stone, and then made available to the entire castle. In the cellar itself stands an arched-shaped scaffolding which is always live, and if power stones on a rolling cart are pushed under the scaffolding, a flash goes into them and recharges them. It is not known how this process occurs and if external control is employed, but the device does not harm operators which frequently enter and exit, swapping out charged power stones for empty ones. The operators also don't seem to wear any specific protection against the device, which suggests that the device is not harmful to organic matter, and only selectively affects Spellbin