Ah, I missed this! It's always good to see Nia kicking ass.
That said, I remember last chapter ended with Loli Grandma still fighting G-Cup to protect Nanao. While she had the upper hand, I don't think their fight was finished.
That had to be the most painful looking weapon in the series. Youkai must have crazy durability because that would have crushed the ribcage of a human.