Classic Light Novel title giving you the basic premise for the story. And another entry in the 'kicked out of the hero party' sub-genre which seems to have developed a few tropes around it. Mainly that the character is viewed as useless but actually does serve some important function, or their abilities/special skills are considered weak or useless but are actually very strong. This one dials up some that trope by not just kicking her out of the party, but selling her into slavery. There's a fair bit of gore that gets played up due to the Flum's healing ability once the sword mentioned in the title is acquired. Mild yuri elements get sort of shoehorned in, but provide the heroine with some new purpose or direction to keep going with life instead of giving up. Other tropes include the ambiguity of the role of the demons the hero party is supposed to be fighting against versus the chruch that is backing the heroes. The end of the volume teases a lot here, so it really tries to hook the reader in to keep going to find out the details.