Eighth Doctor's regeneration

Given that there were multiple different incarnations to have regenerated from the Eighth Doctor, (PROSE: The Gallifrey Chronicles, The Tomorrow Windows, etc.) the regeneration of the Eight Doctor was subject to largely differing accounts. The Eighth Doctor either regenerated into a "listless" incarnation, (TV: The Curse of Fatal Death, PROSE: The Tomorrow Windows, The Gallifrey Chronicles, etc.) and "pale, aristocratic" incarnation, (WC: Scream of the Shalka, PROSE: The Tomorrow Windows, The Gallifrey Chronicles, etc.) an incarnation suffering from the guilt of killing of all the Time Lords, (TV: Rose, PROSE: Have You Seen This Man?, The Tomorrow Windows, The Gallifrey Chronicles, Doctor Who and the Time War, etc.) or a forgotten incarnation who renounced the name "Doctor". (TV: The Day of the Doctor, etc.)

Many accounts held that the Eighth Doctor fought in the Last Great Time War, (PROSE: Museum Peace, Osskah, COMIC: The Forgotten, etc.) and so regenerated into into the Ninth Doctor after using the Moment to destroy Gallifrey Original; (PROSE: Doctor Who and the Time War) the Ninth Doctor was seen on Earth shortly after, still reeling from the guilt of his actions. (PROSE: Have You Seen This Man?, etc.)

However, other accounts held that the Eighth Doctor had regenerated into the War Doctor with the assistance of the Sisterhood of Karn during the Last Great Time War, having been killed when Cass Fermazzi's gunship crashed on the planet Karn with him aboard. (TV: The Day of the Doctor) This was the eighth regeneration of the twelve-regeneration life cycle beginning with the First Doctor. (TV: The Time of the Doctor)