I too marveld at the logic that if two high explosive filled warheads couldn't hurt the giant octopus then the next best course of action would be for Papa to go out with a spear.

For me though, the highlight of this episode, much like every other episode of this series, was every scene that involved Minato doing anything. She is such an awesome girl/Imouto I fully support any potential wincest vibes. While I am extremely jealous of the main character guy (I love how his name simply doesn't matter at all) for having the opportunity to be around such an epic level sister I'm also proud of him for so blatantly making the other girls aware of how utterly uninteresting they all are in comparison to Minato.

I really hope they stick with this thread instead of doing the stock "push main towards the completely undeserving Rie Kugimiya-voiced character, leaving the much hotter and much better over all girl to twiddle her thumbs or pine from afar.