Warning! Major spoilers for the Attack on Titan manga below!
The war between Eldia and Marley in Attack on Titan has gone in a much different direction than fans had ever expected as it turned out that Eren and Zeke had a much different plan in mind. With the hopes of euthanizing the population and slowly eliminating the Titan threat by letting humans die out slowly, this has made Eren enemy number one. His Founding Titan power is still a major threat to Marley too, and they unleashed a surprise attack on the Paradis.
Leading the pack in this surprise attack is Reiner, and he and Eren get into their third big Titan fight in Chapters 117-118. But there's some major differences this time as there are a lot more outside influences. It's not a straight one on one.
As the fight between Eren and Reiner gears up as the two transform into their Titan forms, it's clear that this is part of Marley's plan to war down Eren overall. Eren manages to land a few decisive hits on Reiner, but soon Porco interferes with his Jaw Titan and the fight becomes two on one. They managed to hold Eren down, but he keeps himself alive with the use of his newly acquired War Hammer powers.
But this keeps Eren in one place, and here he's shot in the head by a special gun atop the Cart Titan. Though his brains keep getting blasted out, and Porco and Reiner attack from all sides, Eren continues to counterattack. It looks like Eren is on the ropes, but he grabs the Reiner's jaw and prepares to rip his head in half. Reiner had a counter for this ready to go, but soon another wrench is thrown in.
Zeke arrives in his Beast Titan power, fully recovered, and saves Eren from being defeated. Zeke's thrown rocks pin down both the Jaw and Armored Titans, and Eren is able to slip away for now. But he's still got to deal with the rest of Marley's forces. Marley is seemingly throwing everything they have left in one last desperate struggle so it's going to be a fight through every next chapter. Besides, Eren and Reiner still need to settle things.
Attack on Titan was originally created by Hajime Isayama, and the series has since 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. The lead character, Eren Yeager, ends up joining the military with his two childhood friends Mikasa and Armin after the Titans break through the wall and attack his hometown. Now Eren, Mikasa, and Armin must survive in a world where they not only have the Titans to fear, but the very humans they are trying to save. You can currently find the series streaming on Crunchyroll, Funimation, and Saturday nights on Adult Swim's Toonami block.