Eren wasn't born evil. His fate by the end of Attack on Titan was a result of a plethora of experiences and losses he ...
The revelation that Mr. Kruger from Marley was Eren Yeager in disguise was one of the most surprising twists in Attack on Titan. Falco is completely fooled, but Reiner instantly recognizes him.
Hajime Isayama's Attack on Titan is known for incredible foreshadowing, but the biggest one was seen in the first season which fans couldn't notice.
After finding the truth about the world, Eren walked on the path of becoming Attack on Titan's antagonist. He caused the Rumbling and trampled across the globe and caused the deaths of billions.
In this part, Eren also got his hands on the War Hammer Titan, which increased his power ... dissuade him from completing his plan. Armin and Reiner tried their luck, but it was to no avail.