We may as well just go on ahead and put the SPOILER WARNING in the first sentence, given how monumental the most recent chapter of Attack On Titan's manga (Chapter 124) was. After becoming the Founding Titan, we watched as Eren undid all Titan hardening, freeing the Colossal Titans trapped in the Walls on Paradis Island. Destined to trample the earth, these Colossal Titans will exterminate all life on the planet, excluding the inhabitants of Paradis Island.
At the time of this article's publication, the Colossal Titans have only just begun to move, so we can't say for sure whether or not Eren will really go through with this plan, although that hasn't stopped us from deliberating whether or not this was the right thing for him to do.
10 Right: The Other Titan Shifters Have Lost A Powerful Ability
As the Walls collapsed, so did the Armored Titan's body armor. Without his armor to protect him, Reiner's just as vulnerable to the blades of an experienced Survey Corps member as much as any other Titan, but he's not the only Titan Shifter who relies heavily on hardening to get the job done.
The War Hammer Titan creates weapons out of hardened flesh, the Beast Titan can harden his nape for protection, and the Female Titan can not only do the same but can also solidify her feet and hands to give her attacks an extra kick. After Eren rendered all hardening obsolete, however, Titans who can harden their skin have lost a prominent advantage, tipping the scales in favor of the Eldians.
9 Wrong: Annie Has Been Freed
Out of all the Titan Shifters on Marley's side, Annie might be the most dangerous. Her unrivaled stamina and arsenal of diverse abilities make her fit for any situation. If she were present for the Battle of Shiganshina District, the Survey Corps wouldn't have stood a chance.
At the end of Chapter 124, it was revealed that in undoing all Titan hardening, Eren also freed Annie from her crystal barrier. While she did miss out on a lot, we're sure she wouldn't hesitate to crush anyone in the Survey Corps without a second thought. Something tells us the death toll will only rise in future chapters.
8 Right: He Was Left With No Other Choice After Marley Invaded
After Marley brought the fight straight to Paradis, Eren was left with few options. They forced his hand and didn't give him any time at all to reconsider this masterplan of his. Not only did he have to worry about the Jaw Titan, Cart Titan, and Armored Titan, but after Zeke turned several Eldians into Titans, the chances of Eren losing his life during the battle only skyrocketed.
If anything, the sight of so many Colossal Titans out in the open is a sure way to get Marley to leave Paradis alone for good, but if only they kept their distance, maybe Eren could've come up with an alternate plan to end this centuries-long conflict.
7 Wrong: Innocent Eldians Will Be Killed
After tearing down the Walls, Eren decided to protect only the Eldians of Paradis Island. This means that the Eldians living in Marley will be exterminated with the rest of the world, despite being hated just as much as the Eldians of Paradis.
Without the Walls to act as a barrier, Zeke's Titans are free to roam wherever they please, and their victims will have nowhere to retreat until all of the Titans are slain. Friendly nations like Hizuru will also be crushed, even after they've proven themselves as allies of Paradis Island. When all the smoke finally clears, we're confident that Paradis, along with the rest of the world, will have suffered some pretty heavy losses.
6 Right: Eren Should Protect His Homeland
Although his father's side of the family lives in Marley's internment zone, which he's lived in himself for several weeks, Eren decided to protect only the Eldians of his homeland.
We can't blame him for this since it was the people of Paradis that he fought alongside for so many years, and while he may understand the Eldians of Marley a little bit more, he has no emotional connection to their community. At least some of our favorite characters will make it out of the Rumbling alive, even if the rest of the world doesn't.
5 Wrong: Confirms What The Rest of the World Thought About Eldians All Along
Due to the actions of Ymir Fritz and her descendants, the rest of the world sees all Eldians as devils, but as Jean said in this most recent chapter, the fact that the rest of the world tried to kill these "devils" led to Eren eventually guaranteeing their destruction. Whether or not he made the right choice, destroying the world is something that only a true devil could pull off.
If he actually goes through with this plan, he not only validates Marley's claims that the Eldians were a danger to the rest of the world, but he also perpetuates the cycle of Titan violence that existed ever since Ymir Fritz used her powers to crush other empires. By carrying out his masterplan, Eren, much like Ymir, will be using his Titan powers to the benefit of a small group of people while screwing over the rest of the world. And let's admit it: his new face has "devil" written all over it.
4 Right: The Walls Can't Remain Up Forever
"The Walls can't hold forever." Armin spoke these words in the very first episode, and despite his limited knowledge of the world at the time, his words still ring true today.
Let's say Eren solved this entire conflict without having to tear down the Walls. The Walls would still create an aura of separation between Paradis and the rest of the world, serving as a constant reminder of what would happen if someone got on the Eldians' bad side. Even in times of peace, Paradis would be feared. Not respected. And we all should know by now that nothing good comes from fear.
3 Wrong: Zeke's Method Was Less Violent
Zeke wanted to use the Coordinate to sterilize every living Eldian, which guaranteed their extermination after they all grew old and died without propagating their bloodline.
While it is a depressing plan, it's also particularly nonviolent for a series where characters being eaten alive is the norm. If Zeke carried out his plan, Eren, Armin, Mikasa, and the others would've been able to live the rest of their lives on Paradis Island without having to worry about any external threats, and with what they've been through, maybe a childless retirement isn't the worst thing...
2 Right: It Was Either Paradis Island or the Rest of the World
After Marley took the fight to Paradis Island, it was clear that even if they did manage to repel this initial attack, the rest of the world would lead a global assault that would overwhelm the Eldians. The natural resources on the island would be too tempting to abandon after a single failed attempt.
Part of us feels like Eren made the right call, given that it's nearly impossible for Paradise Island to coexist with the rest of the world.
1 Wrong: Eren Could've Commanded Zeke's Titans To Eat Only Marleyans
Even when he unintentionally used the powers of the Coordinate, Eren was able to bend Pure Titans to his will, yet after becoming the Founding Titan, Eren made no attempt to stop Zeke's Titans from consuming any Eldian in sight.
Maybe he was preoccupied with The Rumbling and the Founding Titan is just bad at multitasking. Regardless, Zeke's Pure Titans were allowed to devour the very same Eldians that Eren swore to protect, and given that his friends were the ones who fought these Titans, they were definitely put in even more danger. If Eren had just commanded these Titans to eliminate only Marley's soldiers, we could've all been spared the heartache of witnessing Pixis's final moments.