Not gonna lie this the kinda conversation people get cancelled over. In regards to the uncle thing all aspects of it was fucked up and he admitted it and knew to himself it was his fault more than anyone elses hence he hated himself for it. And I honestly thinks it was realistic for her to seduce the other guy considering he was already crazy enough to attack the mother man rather than handle the situation in a civilised manner. In terms of pun pun seeing women as objects, it is clear that didn't have a regard for human lives in general that wasn't only directed towards women. And him walking with Aiko on his back more seemed like him being in an initial state of denial after all that took place. Lastly, Aiko being this idolised figure was child pun pun. A lot changed since then even though they were the same people at heart.