I forgot the title

Manhwa/male mc/system and dungeons in south korea - so what happened is: all humans transmigrated to a different world to train from the monsters' attack that will come soon on earth, but the mc was left out alone due to some error (time has stopped on earth) a girl accompanied him sometimes (I guess she's an angel or someone who can manage the system). The mc learned every skill he could learn on earth since he's stuck on earth for thousands of years. Then...one day, all humans came back, some awakened their abilities, some remained normal citizens. Then, the apocalypse or monster attack from the rift started to occur. He's still connected to those angel beings, then he opened a smithy and forge the angels some weapons. I didn't know what happened next, the story might be jumbled but that's all I remember. If you know the title of this manhwa, please let me know, I've been trying to look for it for weeks now, I couldn't find it.