User blog:Sky-Dragoon-Twilight/Are the Wall Titans allies or enemies?

The wall titans are one of if not the biggest mystery in the series so far, and until the events of Episode 25/Chapter 34 only the Wall Cult had any knowledge about them. Taking to account how the 3 walls were built after the Titans took out most of humanity this leads me to wonder not only how the walls were even built but which side the titans inside are actually in. There are some clues and actual pieces of proof that gives some ground for both the Wall Titans being Allies and Enemies.

 Hints to being allies: 
 * Humanity had no knowledge on how to fight the titans when they first appeared
 * With the time it could have taken to make the walls by hand, the titans would have likely devoured all of inhumanity before they could finish
 * Since like most titans they need sunlight to function if the walls were built using them they could have easily attacked any human when the sunlight began to power them

Hints to being enemies
 * Pastor Nick asking the walls to be covered before sunlight hit them
 * The only one we actually see faintly turns its eye toward Mikasa
 * The fact that the memories of the outside world have faded from human memory and the Wall Cult hiding their existence from the rest of humanity.

Either way, the exact motives for why they even made the walls are unknown alongside with who they are sided with. And should they break out of the walls, will they exterminate humanity like the many others or protect it like Eren without his Coordinate ability?

What do you think? Are the Wall Titans friends or foes to humanity?