SPOILERS AHOY For Gotham Season 2 Finale.
Well, that was a doozy, now wasn't it? After a year of villains rising and wrathing all over the place, the good guys finally won one! Or did they? After all, Hugo Strange is still alive (though yes, in custody), Mr. Freeze and Firefly presumably escaped, Fish Mooney is back out on the streets with THE POWER TO ENSLAVE MINDS, the Court of Owls is still safely in secret, Jim Gordon's leaving Gotham City (temporarily), and oh yeah, a bus full of monsters was let loose.
And that brings us to the bus full of monsters. They were kept largely in the dark, likely on purpose, so they can decide next season exactly who was on the bus. There was a scaly-faced one, likely Gotham's version of Killer Croc, someone with Don King/Bride of Frankenstein hair, and someone with a mask that covered their mouth and right eye in bedazzled leather like an anime character. Feel free to speculate in the comments as to their identity. We, however, are much more curious about the very last "monster" we saw: actor David Mazouz, who plays Bruce Wayne on the show, in a long haired wig (one assumes).
Yes, that's definitely Mazouz, but just who is the character he's playing? There are two likely options, and they're both aligned with the real big bad of the season, the Court of Owls. After their reveal this season, it's only natural that they'll be a much bigger presence next year.
First, and perhaps most intriguing option is Thomas Wayne, Jr. There have been many versions of the character, sometimes a little older than Bruce, sometimes a little younger. Sometimes he was presumed stillborn, sometimes he was sent off to a (non-Arkham) mental asylum. The newest version was a combination of these, according to him anyway, sent to a "Home for Children" after being born prematurely. The character was taken in by the Court of Owls, and, as Lincoln March and Owlman, he wreaked havoc, both upon Batman/Bruce Wayne, and upon the Court of Owls, as well.
It wouldn't be a stretch, then, for Bruce in this world to also have a brother - maybe even a twin brother, who is looking to take the Wayne name back at any cost. It's possible the character will pull a bit of a "Hush," wherein a villain (in the comics, Tommy Elliot) tried to take over Bruce Wayne's life, and engineered him having to take on his greatest villains.
The other possibility is that he'll be Bruce's ancestor - hear us out. The Talons are reanimated soldiers of the Court of Owls, and they're all connected to the oldest families in Gotham, and yes, that can even include the Waynes. If this particular character, reanimated by Hugo Strange in Indian Hill, comes form another era, he may be a little easier to manipulate for the Court.
Either way, it looks like Bruce Wayne and Gotham City are going to have their hands full in season three of the series, despite what seemed like a victory in the season finale. Bruce thinks right now that he wants to find out about this secret council, but will he really like what he sees when it's staring him in the mirror? We'll find out next year on Gotham!