What if Marcel didn't die?

A series of oneshots exploring different directions the story of Attack on Titan could have gone, including but not limited to alternate character decisions and/or what could have happened if Eren had used the full power of the Founding Titan earlier in the story. NOW INCLUDES A LESS DUMB ENDING TO THE MANGA

What if things had gone differently under Lake Laogi? What if Aang and his friends had heard the conversation between Zuko and Iroh? What would have happened from there? (AU where Zuko joins the Gaang in Ba Sing Se.)

A story that takes place during the episode Betrayal, and details how Beast Boy tells his friends about Terra's treachery.

How would things have played out if Zuko and Jet had remained friends for a little longer? And what would have happened if Jet hadn't died?