Eren Yeager is the protagonist of the manga and anime series 'Attack on Titan'. He is a passionate, impulsive, and determined individual, always striving for freedom from the Titans that have plagued humanity. Eren has a complex personality, shifting between dark, vengeful, and protective. His personal tragedy of witnessing his mother's death at the hands of a Titan fuels his hatred towards them and his strong desire to fight. He joins the Survey Corps to battle the Titans and to uncover the truth behind their existence. Eren has an intimate relationship with his childhood friend Mikasa Ackerman and a bond with his adoptive brother Armin Arlert, which influence his decisions and growth throughout the series. His journey is marked by significant physical and emotional transformations, including the possession of the Founding Titan's power. Eren's relationships with allies and adversaries, particularly Reiner Braun and the Tybur family, add layers to his character, making him both a focal point and a controversial figure within the narrative.