Electromagnetic torpedo

The electromagnetic torpedo was Rokur Gepta's most powerful Force technique, one of the strongest powers of the dark side, and the greatest achievement of any of the Sorcerers of Tund.

It was, in fact, a lifeform unto itself. Lethal to all other known forms of life, one cubic millimeter of the electromagnetic torpedo could destroy not only all life on a planet but all of the "organic substrate" from which any future life could come. It could thrive even in vacuum. The substance glowed a pale green. How long it took to create the electromagnetic torpedo each time is unknown.

After completing his studies, Gepta developed the electromagnetic torpedo to wipe out all other life on Tund, thus ensuring no other could ever learn the secret to creating it. He then used his power to create special force fields that could block out certain areas of the planet from the torpedo, but even in these areas it would take billions of years for life to rise again. After Gepta's death, the force fields presumably fell. He used similar force fields on a smaller scale to protect himself when handling it.

During the battle of ThonBoka, Gepta used a small sample of the electromagnetic torpedo to wipe out a large contingent of the Oswaft, then destroyed it, in order to blackmail Lando Calrissian into agreeing to his request for a duel. Little did Calrissian know that Gepta's flagship, Wennis, had orders to use the electromagnetic torpedo to wipe out all life in the ThonBoka regardless of who won the duel. Fortunately, the Wennis was destroyed by Klyn Shanga and his fellow Renatasians before it had the opportunity to do so. The only place the deadly substance is known to exist presently is the otherwise dead surface of Tund.

Although part of Palpatine's reason for allowing Gepta to rule the Centrality was to learn the magics of Tund for himself, as part of his effort to master every possible aspect of the dark side, it is not believed he ever developed the ability to use the electromagnetic torpedo. Not only was Palpatine never seen using such a devastating power that would undoubtedly come in handy, Gepta would not be likely to allow any other to learn the secret.