Darth Sion-X

Darth Sion-X was a human Sith who was attuned to the Dark Side of the Force, yet was quite knowledgeableof the Light Side and its ways. Personally, he classified himself as a "Gray Jedi." If it were to have been made public, he most likely would have been removed from the Dark Council before he eventually resigned due to personal reasons.

Personality
As a member of the Dark Council, Darth Sion-X was considered more of a listener and heard out proposals in their entirety. He was one who avoided verbal debates in the Council's chamber, although he did state his opinion on a select few of matters that he excelled at.

Most notably, the Sith was known for his extraordinary intelligence and craftsmanship as he headed the sphere of technology for the Order during his tenure.