Thank you for a great story with a twist, Maparari!

I think you win the unofficial FTS 'confirmed kill count' for this round. That is a serious amount of deaths Shiro's companions have racked up.

"It's only been 532 times," replied the male voice without giving importance.

"533, darling," corrected the female voice with a giggle.

There's something both amusing and disturbing by this banter. It has great flow but the inflection in their tones mirrors their lack of care - making it disturbing (well done)!

Then when it's revealed that the girl is a monster out to hurt Shiro, this great banter continues. The back and forth between the three is smooth and reads like a genuine conversation. I enjoyed your last line, where they remind him how much they're needed and that they're not the only monsters around.