User blog comment:San&Ashitaka/TITAN THEORIES/@comment-13234254-20131016110212

Ok here is my opinion.

At first i believed that Titans were something supernatural, more or less like mythical beings from legends. Well, obvioulsly that can't be true since individual humans have the ability to transform to Titans. So i thought that maybe this people who can transform to Titans have the ability to control these bodies because of injections, just like it happened with Eren. Maybe this serum his dad injected him with wasn't the one responsible for being able to summon the Titan but to control him. Overall, Titans could be humanns who were infected by a disease which transformed them to Titans and cause of that they don't have their human form anymore.

I think we will have to wait until Eren makes it to his basement in Sshiganshina to find out the truth. Until then, we are in complete DARKNESSS!!! xD.