Doctor Who: Series 13 Trailer Breakdown - 20 Things You Must See
9. Incredible Makeup Work - And Is This The Master?
This looks to be the same alien who gets "dusted" earlier in the trailer, right? If not, it could also be a different member of the same race - a race that some fans are speculating is the Ravagers, which were mentioned by the Doctor in a recent teaser.
But the best theory about this glittery dude is that he's actually... the Master. Sounds crazy - but it does make a certain level sense.
The last time we saw the Master, he was fleeing from an exploding death particle - but what if he didn't escape the blast? What if it caught him, reducing him to this withered, skeletal form? Remember, we saw the Master in a decaying form during the classic era, so the precedent for this sort of thing has already been set.
This would also explain why glittery dude says "Our final fight has begun." By "Our" he means him and the Doctor - the two renegade Time Lords.