He's a pretty bad character, going full edgelord after one line of dialogue is not character development. The series makes no effort into showing any progression with him, it's just clear Isayama was bored of the shit character he made so forced a time skip to justify writing a different character that looks like they were copy pasted out of any mediocre Shounen starring an edgy teen protag
What makes Eren Jaegar better than 90% of shonen protagonists?
Charles Collins