Deactivating the Spire

As you may know, Magister Duskwither sent me back here to shut down the power sources that feed the Spire. There are three of them, each located in a different place inside.$B$BUnfortunately, I appear to be too late, and Duskwither Spire has been overrun with strange, magical creatures. While I haven't the expertise to accomplish this task, surely a $c, such as yourself, could do so easily?