As we know that history in Attack on Titan is not clear yet. Many things still unexplained. Several important point to discuss about history : It has been confirmed that Reiss Family is the creator of the Kingdom. They are possessing a power to manipulate human mind except for Ackerman family and Asian race. Titan can be created by injecting serum into human body and after becoming a titan, titan can revert back into human form by eating another titan who has high level than the eater. There is civilization beyond the wall where Berthold, Zeke, Reineer, and Annie come from. And Zeke said that he is one of the victim from Grisha jaeger experiment. Their goal is to destroy human inside the wall . Wall is created by Titan . Several question Where and Why are Titan come from in the first time? What is their goal? How is history in the past? How to create titan serum? Is there huge civilization beyond the wall like inside the wall or it just consists of several people?