Marco's death was one of the more emotionally impacting for Attack on Titan fans, and with recent revelations in the manga, it's become even sadder.
But with the upcoming release of the new OVA special "Wall Sina, Goodbye" featuring Annie, Marco's brutal end will finally rendered in animated form.
Fans may still be waiting on Attack on Titan's third season, but the new "Lost Girls" OVA trilogy covers a bit of story information coming in the future. As the OVA will be bundled with Volume 24 of the manga, the trailer for the Annie focused "Wall Sina, Goodbye" opens with one of the more effective reveals of the manga's later chapters.
The scene depicts Marco's true cause of death, which Jean and the other members of the Survey Corps couldn't figure out when Marco's body was first discovered, as Annie played a key role in making sure Marco would be eaten by a Titan.
In the manga, when Marco overhears Reiner, Bertoldt, and Annie discussing their secret Titan attack plans, Reiner decides to execute Marco because he tended to figure things out exceptionally fast and they needed to keep their power secret.
With Reiner holding him down, Annie removes his maneuver gear and the three leave him stranded on a room to die while a Titan slowly approaches. Marco cries out in anguish as Reiner and the others watch the Titan bite into him. Bertoldt and Annie are visibly shaken, but Reiner hesitates to react before the horror of the scene finally breaks him.
For those unfamiliar with Attack on Titan, the series was originally created by Hajime Isayama. Starting its run in Kondansha's Bessatsu Shonen Magazine in 2009, the series has been collected into 23 volumes as of 2017. It's set in a world where the last remnants of humanity live within a walled city in order to escape the danger of the Titans, a race of giants monsters that eats humans. Eren Yeager joins the military with his two childhood friends Mikasa and Armin after the Titans break through the wall and attack his hometown.
The series was adapted into an anime from Wit Studio and Production I.G. with a third season premiering in 2018. 68 million copies of the manga have been sold as of 2017, and has been met with major critical and commercial success worldwide.