April 6th is Konpaku Youmu Day! 4/6 can be read "yo, mu" in goroawase, sounding like Youmu

← It's Roukanken ("the watchtower sword") It was forged by youkai. It's said that it has the power to kill ten phantoms in one strike. And huge.

← Konpaku Youmu She's earnest as befits a disciple... but also has a naturally pretty immature personality.

There isn't much I can't slash! with the implication of defeating / killing

It's her catch-phrase →

↑ It's Hakurouken ("the white tower sword") It is a sword that has the power to dispel the confusion of those it cuts.

↑ It's her "half-spirit", which can be hardened and used to hit enemies.