uhh i can't remember much about this novel, probably 'cause i only read like 10-40 chapters. but if i remember correctly, at the start of the novel he's in a fight with someone who i think used to be his friend, who was also an elf. (he was like an evil elf tho, or an assassin elf, idk) he was in some sort of organization like an assassin guild. anyway, he gets into a fight with this ex-friend elf, i don't remember who wins, but i do know the mc dies. anyway he goes back in time, and iirc he arrives in this like survival area? with other humans. the mc, along with several dozen, or hundreds of other people. kind of like a tutorial area that also weeds out the trash with no potential. kind of like tower defense, they start with a large group of people, and monsters like goblins and orcs (might not be either of them, just an example) attack them. some people die yada yada, eventually the MC becomes the de-facto leader of most of them, with some other trash on their own who want to kill the mc because... idk? iirc, which i probably don't, after the trial period there are people who take them into their guilds or organizations or groups or whatever. mc in his original life happened to be taken by some sort of assassin guild i previously mentioned. also this world is a world with like elves, dwarves, and shit. and maybe magic? idk it was never mentioned but i'd assume so.
Speaking of forgotten novel. There was another novel where the mc is transported to another world and die there only to travel in time to the starting point. And where he meets the demonic cult successor who teaches him many things.however to increase his power he trains on a mountain where for each particular period of time e he stays there his sense are taken one by one temporarily until he leave the mountain Does anyone know the name of this novel