Major character deaths and mass murders of entire communities are practically a tradition in horror anime. Having memorably gory kills plus a high casualty rate that doesn't spare named characters are surefire ways for a horror anime to gain fame or notoriety. Notable anime, however, went the extra mile.
10 Horror Anime With The Highest Kill Counts
Horror anime often feature high death tolls, but series like Shiki and AOT take it to the extreme, killing thousands or even millions of people.