I was summoned to another world as a hero, but why am I the only one being treated so badly???

Kisaragi Seiya, a second-year high school student at 17 years old in the prime of his youth, was suddenly summoned as a hero to a sword-and-magic fantasy world when the floor began to glow during a tedious career guidance meeting. While the others possessed cheat skills, Seiya alone acquired a strange skill that made him "stronger the more blood he shed," and while desperately hiding it, he ended up being branded as "incompetent." How will Seiya navigate his life in this fantasy world...? Updates are irregular.