Soul Sealer

A powerful binding magic that takes un-naturally used souls and binds them to an object of appropriate size. It was created by a group of gnome wizards as their kingdoms last bastion of safety from an undead army was being assaulted their city walls. Not even their own armies of construct soldiers could keep back the hoards. As the gates where being stormed, these wizards gathered at a large marble obelisk they planned to seal the souls into. It was working, sucking the souls from their undead bodies and sealing them away, slowly turning the marble to obsidian. But then the obelisk was completely turned, and the stone paths of the city started to change as well. Still the souls kept coming, and coming, and coming. The spell was not discriminatory, as it even took the souls powering the constructs and sealed them away. Eventually the entire city became obsidian, filled with the leftover husks of constructs and the rotting corpses of undead.

You can take any soul that is not naturally in its place, like undead and constructs, and channel it through yourself to seal them into an object. Whatever they are put into turns to obsidian. The conversion of soul to amount of space needed is 1 cubic foot per soul. The higher of spell level you cast it at the further it reaches. However there is potential for the amount of souls rushing through your body to essential fry your own soul. - Lasersniper