Sigil

Sigil is an Degasi/Immortal and the second user of Mrethus' Flower. He used it to create a universal balance of good and evil, life and destuction. He is antagonized as the murderer of the Originator, the being which created life, but he argued that he did it because the Originator was too powerful a force for good. He was also the second Emperor of the Universe.

Powers
Sigil was one of the most powerful beings in the universe. He possessed godlike powers even when he was not using the Flower. He was the king of the Degasi and ruled the nest under a strict but fair hand.

After learning of Mrethus' Flower, Sigil left on a quest to find it. Along the way, he founded the Sigils of Balance, an order of beings whose only purpose was to counterbalance good and evil, respectively. This was Sigil's philosophy.

Once the Flower was his, he used its power to spread his philosophy across the known expanses of space and kill the Originator to become the second Emperor of the Universe. He ruled for thousands of years under a strict but fair hand, destroying evil and good in fair and equal amounts.

He was eventually banished by the third user of Mrethus' Flower (for complete list of users of Mrethus' Flower, see here) and is officially known as dead. However, his confirmed appearance in Final Stand may discontinue this idea.

Appearances
Icarus - He is mentioned by someone selling the Tome of Ark.

Final Stand - It is confirmed that Sigil will make an appearance in Final Stand, whether mentioned or actually shown.