After the intensity of The Force Awakens, what can J.J. Abrams do in Episode 8 to capitalize on the success of Episode 7? Tell us more about the epic dude in the above photo, of course! The mysterious trooper affectionately nicknamed "TR-8R" after his new catchphrase of "Traitor!" was, according to the canonical novella "Before the Awakening", as well as the "Star Wars The Force Awakens Visual Dictionary", actually a member of a four-man squad led by none other than our hero, Finn. This being the case, it narrows down his identity to one of three potential candidates.
The three troopers under Finn's command each had nicknames, although Finn himself did not. The troopers were known as "Nines", "Zeroes", and "Slips". Their numerical designations were FN-2199, FN-2000, and FN-2003. Nines and Zeroes each received their nicknames because of the last two digits of their stormtrooper numerical designations, while "Slips" received his because he was always slipping up. The Force Awakens Visual Dictionary confirms that the trooper who dies during the raid on Jakku was Trooper FN-2003. Likely then, this trooper was the one known as "Slips". Now that leaves only Nines and Zeroes as possibilities for TR-8R's identity. Lucasfilm confirmed that TR-8R is, in fact, Nines.
So, that brings up the obvious question... if Zeroes is still out there someplace, and he is well aware of Finn's treachery, (as he no doubt is based on the fact that Nines knew about it), who's to say that Zeroes isn't going to come after the greatest thing the Resistance has ever had happen to them? Maybe he wants revenge for Nines' death. And if Zeroes does indeed come after Finn, can we expect to see another "TRAITOR!" scene? Or will it be even more intense when Finn realizes he must now fight to the death the last member of the only family he ever remembers?