Wait what? Little sister died? Why? Wtf is that lol
In one of the earlier chapters (57 or 58) it was stated, or at least implied, that using the flute to summon the monster would result in the death of the sister, however the trade off is that the monster would continually and act under the sister's command until her death. However, because of Olivia's saintess power that was robbing everyone of their will and strength to fight, this also affected the sister (and by extension the monster under her command) and thus resulted in the sister dying and the monster dying (as well as the flute breaking). At least that's my take.Wait what? Little sister died? Why? Wtf is that lol