Kenossium

The General was a Time Lord military commander who led the efforts to defend Gallifrey from the Dalek onslaught in the final days of the Last Great Time War.

Biography
In the aftermath of the Fall of Arcadia, he was made known of the Doctor's appearance there and was alerted to a security breach in the Time Vaults, discovering that the Doctor had taken the Moment, the last weapon in the Omega Arsenal.

He was later contacted by three incarnations of the Doctor, the War Doctor with the Tenth and Eleventh Doctor, who revealed to him their plan to save Gallifrey by freezing it before its destruction and shifting it to a pocket universe. The General was skeptical, but with the Dalek fleet closing in, he soon gave the order and all 13 Doctors performed the process together. (TV: The Day of the Doctor)