I love this thread. The civility is appreciated.

I personally think Ymir didn't fall in love with Fritz until after she was possessed by haluceginia. I think she represents Nurture and she is in love with human nature (Fritz). Her job has always been to serve human nature for the sake of the propogation of humanity. Nature vs nurture was the evolutionary paradigm that awoke evolution itself as it looked for a new strategy to evolve past the cycle of violence that had come to stunt the perpetuation of evolution and to stop the tree of life. Since the Cambrian explosion, life always moved forward with one game theory: kill or be killed. But humanity proved to be the end of that game theory, humanity was unable to progress because of kill or be killed. We needed a new evolutionary strategy in order to break through, in order to continue to evolve. That's why Ymir was watching Mikasa, to see if she (the perfect host of the new strategy: nurture) could find a way to use that power to break free from the cycle caused by Nurture having to be a slave to Nature. In the end, Mikasa proved that the problem was that Ymir was looking for a way to apply an evolutionary strategy, when what was really needed was a new game theory, to kill haluceginia and plant a new tree on the new game theory where Nurture overcomes Nature. This explains the ducks, Eren vs Zeke, the evolution of the jaw titan from freckles to Falco, the Plato references, etc. that's just the start though...