User blog comment:Gourgeist/Shingeki no Kyojin Chapter 63 Review: Chains/@comment-24.237.36.25-20141208222037/@comment-4929778-20150822232328

I think Eren is one of two things 1. A Reiss descendant through any way, like being an illegitimate child or whatever or 2. He isn't a Reiss and Haijime just intentionally drew Frieda to look like Karla to confuse us. If Eren were a Reiss he'd fall under the First King's ideology and not use the coordinate. Frieda knew everything while having it in three years whereas Eren it's been 5 and he knows only what Grisha did.