Attack On Titan: Are Mikasa And Levi Ackerman Related?

For those who watched up to the ending of "Attack on Titan" Season 3 or read Hajime Isayama's manga past Chapter 63, they know that Mikasa and Levi are related. Along with Kenny, who is revealed to be Levi's uncle before his demise, these characters are all from a dying family line known as the Ackermans. 

This family, which existed for generations prior to the building of the walls, were supposed to serve as the royal family's sword and shield. That was until they turned their backs on the King's ignorant ideology. Due to the abandonment of their duty and the threat they posed as combat specialists, the Ackermans were hunted down and persecuted.

As of Season 4, there are two living Ackermans that audiences know of: Levi and Mikasa. Their connection was acknowledged in Chapter 63, when, on the way to rescue Eren from Reiss and his underlings, the Survey Corps Captain asks Mikasa if she ever had a moment in her life when she felt a power awaken in her. Mikasa did experience this, recalling the traumatic night when she first met Eren.

Although it is acknowledged that Mikasa and Levi share the same blood, there are still doubts among the fanbase concerning how the two are related. Like others online, this Reddit post's OP wonders what familial relation links Mikasa to Levi. 

In response to the aforementioned post, there were a few insightful answers, even though "Attack on Titan" never gives a concrete solution to this query. One of these responses came from u/MatemanAltobelli, who explained to the OP why the two highly-skilled fighters are likely not cousins.

"Kenny and his grandfather talked about this in a flashback," they posted. "A branch of the Ackerman family moved to Shiganshina. That's where Mikasa's father came from. So in other words, Levi is the last Ackerman from the main family (that lived in the Interior); Mikasa is the last Ackerman from the branch family (that lived inside Wall Maria)."

This flashback appears in Season 3, Episode 6, "Sin." The connection between Kenny, Mikasa, and Levi, is then explored further in Episode 10, "Friends," in which the mid-roll screen addresses their blood ties.

Another fan, u/Razzylada, follows a similar reasoning. After acknowledging that Mikasa and Levi's exact relation isn't known, they allude to that same flashback to make their argument. 

"Based on Kenny's grandfather's words, he talks about another branch of the family moving near Shiganshina," they posted. "Using these words means that they're not his own descendants, so they could be descendants of his brother, or his first cousin, or something like that. Could be even his second or third cousin. We don't know at all, but the closest would be them being descendants of his brother/sister, making Mikasa and Levi, at best, third cousins."

In this sense, "Attack on Titan" fans are more or less on the same page as Levi and Mikasa. Although they know of their common bloodline, they could not use the little information that is available to draw their own family tree to figure out how are closely related they are.