Seriously speaking,i don't even know if there's a novel with this tags. *So I'm loking for an mc who cool headed and doesn't rush in to a fight and dies because of a friend *A little bit of an op and low-key *(Sensible or no harem with no "chapter 1-our enmity will never fade then ,chapter 200-and he fell in love with her ") *Someone eyes never narrows "like a pinhole camera" even if the world is ending *frequency lucky guy who likes looking for treasures and also, mc should be a bit greedy
The first one that comes to mind to me is Zhanxian. This is a cultivation novel with harem. Not sure this is what you're looking for. After rebirth MC's main concern is getting to know his master again and protect her. MC is quite OP but hides most of his strength until the end of the novel and deals with his main enemy in a hidden way. He does become very well-known for his pill making though. A lot of the women that are added to his harem are added because of force/compulsion. The sects these women come from are more powerful than his own sect and his sect has trouble rejecting them. His main wife (master) does agree to adding all the women to the harem and convinces him to accept most of them. Because of his rebirth and because he learned a lot from people he executed as an executioner (because of a revolt on higher level world) he knows many places where treasures will appear.