The show's defining trait — willing to kill major, well-liked characters without the usual genre-safety assumptions.
Diverges from the manga due to the anime's production catching up to ongoing publication — a similar situation to Tokyo Ghoul.
Generally considered more coherent and closer to the story's originally intended direction.
No — the anime's production reportedly outpaced the manga's ongoing publication, resulting in an original anime-only ending that differs from how the manga concluded.
Yes — this is the series' most distinguishing trait, breaking from the genre convention that assumes main cast members are generally safe from permanent death.