Although Eren Yeager and Light Yagami are from two separate worlds, the pair share a common goal of wanting to balance the books of an unjust system. More often than not, this often leads to death; hence, the titling of the Death Note series — and Attack on Titan is, of course, no stranger to that concept as well.
But now the question remains: Who is the true evil protagonist between the two legendary anime? Could it be the infamous Kira, or will the new Founding Titan wielder be the one who reigns supreme? The only way to determine the winner of this battle is by looking at their arc as a whole and the reasoning behind their sinister acts.