War Doctor's regeneration

"I hope the ears are a bit less conspicuous this time."

- The War Doctor's last words

The War Doctor, who himself regenerated from the Eighth Doctor, (TV: The Night of the Doctor) met his regeneration into the Ninth Doctor within his TARDIS, having felt his body "wearing a bit thin" after working with his other incarnations to end the Last Great Time War by relocating Gallifrey to a pocket universe, (TV: The Day of the Doctor) allowing the change to happen after fighting it for years. (PROSE: The Day of the Doctor) This was the ninth regeneration of the Doctor's first regeneration cycle; as the ninth incarnation generally did not identify as the Doctor. Despite this, the Eleventh Doctor noted that it still counted as a regeneration which, combined with the Tenth Doctor's siphoned regeneration, made the Eleventh Doctor the thirteenth and final incarnation of the Doctor's regeneration cycle. (TV: The Time of the Doctor)

However, many other accounts indicated the Eighth Doctor fought in the Time War (COMIC: The Forgotten, Don't Step on the Grass, PROSE: Museum Peace, Osskah, etc.) and subsequently regenerated directly into the Ninth Doctor. (COMIC: The Forgotten, PROSE: Have You Seen This Man?, Doctor Who and the Time War, etc.)