Read Fukushuu Kansuisha no Jinsei Nishuume Isekaitan Manga:
Kousuke Kurono was an Avenger. After being raped, his beloved little sister was left out in the cold and froze to death. From the time he was 13-years old, Kousuke made use of any possible means in order to exact his revenge. 5 years had passed, he achieved his revenge, but having lived solely for the sake of revenge, at the moment his revenge came to fruition, afterwards he c more.. ouldn’t muster up the willpower to live on. That’s why, with the same knife he used to kill the culprit, he slit his own throat. However, he then heard a voice; “Is that not wasteful?”. When he came to, he found not his home, his country, nor his world——It was another world.