hashiras react to giyuu's father as muzan

Some of the hashiras who died in the manga include Gyomei Himejima and Muichiro Tokito.

Muzan was ultimately defeated by the collective efforts of Tanjiro, Nezuko, and the other demon slayers. Their teamwork and perseverance were key to ending Muzan's reign of terror in the manga.

Tanjiro Kamado and his allies managed to defeat Muzan. Their combined efforts and determination were crucial in the final battle.

Yes, Muzan does die in the manga.

Yes, Giyuu did die in the manga.

Yes, Giyuu does die in the manga. It's a sad moment for fans.

Yes, Giyuu does die in the manga. It's a sad moment for fans.

Yes, Tanjiro does manage to kill Muzan in the manga.

I'm not sure exactly, but you might be able to find the answer by looking closely at the final chapters of the manga or related discussions online.

There are fanfictions where Shinobu and Giyuu are paired in a post - demon - slaying world. For example, they might start a new life together, perhaps helping to rebuild the demon - slayer corps in a different way. Shinobu's medical knowledge and Giyuu's combat skills could be combined in interesting ways in these stories.