I've been reading this manhwa all year. I'm currently 55 chapters into Nano Machine. It blends fantasy with science fiction and adds a load of characters -- each crucial to the story. Add in martial arts and a well-developed fantasy world and you have a story that will grab you and keep you coming back for more!
The main character is Cheon Yeo-Woon, an orphan from a Demonic Cult. His mother was not one of the High Priest’s official wives, but his father’s holy blood is still considered to flow through this body. It is more of a curse than a blessing, as other worshippers in the group are trying to kill him. When an unexpected visit from his descendant in the future gifts him with a nanomachine, Cheon Yeo-Woon’s life (and body) are drastically changed.