He studied deeply the arts of Sauron, the better to oppose him, but he soon became enamored of Sidious's devices, especially the lightsaber. He betrayed his mission and sought the power of the sword for himself. He initially advocated an alliance with Sauron and Sidious, but he soon betrayed them as well, as his ultimate goal was to supplant Sauron and rule Middle-earth. But his plans came to nought, and his power was broken in the Battle of Coruscant.
Before his fall, he was the chief of the Middle Earth wizards and of the CIS(The Confederacy of Independent Systems). His knowledge and skill, especially of Sauron and Sidious's devices, was said to be great. However, his deep study of the lightsaber and Sidious's other magic corrupted him, and his overweening lust for power led to his downfall. He is one of the few participants in the Great Intergalactic War who was morally "grey" - serving neither good nor evil. He betrays both sides and ultimately works for his own rebels, the CIS.