Hello, I've forgotten the name of a novel. Here are the main points of the first few chapters -MC is male and is one of the last heroes on earth after monsters invaded -He kills a former friend that is part of a death cult trying to change history?? -MC dies but is brought back to the past due to former friend's death cult ring -Former friend visits MC and gives him future advice to save the "unknowing" MC from a bad family situation the day or so after MC's parents die, but also takes the MC's original class and gathers the strongest heroes -The MC hides his reincarnation, but goes on a mountain hike to get a secret class even stronger than his original As you can see, I've remembered a good amount of the details, but it's name eludes me. Any help is appreciated!