Eren Yeager started The Rumbling for the same reason Walter White became a drug kingpin in "Breaking Bad", ie. "I did it for me." As Eren tells Armin in the very last episode of "Attack on Titan ...

Eren's attack on Marley was a political demand to safeguard Eldia. Eren's actions as the Founding Titan made him a slave to his fate, leading to the Rumbling. Eren's journey of chasing freedom is ...