While Black Whirlwind and Henpecked Hou protect the Temple Courtyard of Dirge from Lotus Assassins, go to the opening room (not behind you down the stairs) to the player's left. An invisible chest is against the wall between two of the standing towers. Walk near it and it will appear.
Maker's Bane was forged from a falling star that tore from the heavens as the Celestial Dragon shaped the world. The loss of life resulting from its use is thoroughly predictable.
Placid Guiju is a sepulcher for the God of Agricultural Poetry. Guiju of Words and Land transformed into a plowshare to aid the workers of the Golden Delta, but was trapped when the farmers remade their tools into weapons to repel invading Horselords. Pounding plowshare to sword might have held ironic appeal, but being an axe causes injury to Guiju's poetic sensibilities. The effectiveness of this blade is agony for his gentle spirit, an insult that will eventually destroy him and strip "field verse" from the Lexicon of the Ages. It also makes the wielder slightly giddy.
The Black Whirlwind's weapons can harm spirits.