|Residence||The Mother of Invention (formerly; deceased)|
|Powers and Abilities|
|Alias||"Sigma" - Officially Speaking|
|Voice Actor||Elijah Wood|
|First Appearance||Metamorphosis (BBO)|
Sigma has the appearance of a man who is on fire. He is transparent, and his flames are orange. Sigma takes the appearance of a balding man.
Meta Sigma has grown a large- for his size- pair of skeletal wings. That is the only difference.
Like his partner, Sigma is calm and collected for most of his appearance. He was the first A.I. to bring up the Alpha, which is a myth according to the Counselor. As Meta Sigma, he takes on a much more aggressive manner, actively pushing Maine to fight and harm Bowman.
- Metamorphosis (BBO) (first appearance) (death)
- A much deeper distortion in tone can be heard echoing whenever Sigma speaks.
- Sigma's voice actor is Elijah Wood, who is most known for his leading role as Frodo Baggins in the Lord of the Rings film franchise.
- In mathematics, the capital Sigma (Σ) is used to represent the addition of elements and/or mathematical terms, similar to how Sigma attempted to combine (add) all the A.I. together, in order to become the Meta.
- Sigma appears to be the most powerful A.I., as he was able to possess Maine and force him to fight Bowman.