Sontaran-Prime

In an alternate timeline where the Cybermen used Time Lord resources to conquer all of history, the Sontaran-Prime was a first-generation Sontaran, and the leader of the Last Great Sontaran War Fleet in the 24th century following the Sontaran Empire's near-complete destruction by the Cybermen. (COMIC: Supremacy of the Cybermen)

History
In the 24th century of an alternate timeline, the Sontaran-Prime ordered a squad of Sontarans, led by Commander Sturg, to capture the Tenth Doctor for his assistance in the Sontarans' war with the Cybermen, who had destroyed nearly the entire Sontaran Empire in a campaign to eradicate any species that would constitute a serious threat to the Cyber-Empire.

Following the capture of the Doctor, Gabby Gonzalez and Cindy Wu at the Cosmomart, along with the crash-landing of the Imperial Flagship on Sontar due to an attack from the Cybermen, the Sontaran-Prime explained to the Doctor the reason for his capture, and ranked him as field marshal of the Last Great Sontaran War Fleet. When the Cybermen began teleporting onto Sontar and attacking the Sontarans, a Cyberman teleported behind the Doctor and attempted to kill the Time Lord; the Sontaran-Prime shielded him from the Cyberman's blast, and was killed. In a state of shock, the Doctor briefly mourned the Sontaran-Prime before Sturg killed the Cyberman and informed the Doctor of the approaching CyberKings.

At the end of the universe, when the Twelfth Doctor and a betrayed Rassilon used the Eye of Harmony on Gallifrey to regenerate the universe, the Sontaran-Prime's encounter with the Doctor was erased from history, as were the rest of the alternate timeline's events. (COMIC: Supremacy of the Cybermen)