A cryptic vignette aired during this week's episode of NXT which seemingly teased the return of a former champion at next month's TakeOver 31 event.
The promo began with night vision footage of a mysterious figure walking through a warehouse towards a glass case with the original versions of the various NXT championships inside. He/she then smashes the glass and grabs one of the titles while speaking in a distorted voice.
“I’m not sure what happened. I helped create something out of my own blood. Years and years of dedication, only to be taken over by paper champions. These NXT Championships have been in isolation for far too long. Now, I’ve come back to take what is mine.”
Assuming this is a man (there's a theory that it'll turn out to be a female Superstar, but that seems unlikely), the most likely possibilities are Bo Dallas or Bobby Roode, who haven't been seen on the main roster in quite a while. Taking into account those "helped create" and "paper champion" hints, we'd say Dallas is the better guess.
Whoever is it, they're going to return/re-debut at next month's TakeOver, so we may get a few more hints during next Wednesday's episode.