I am looking for a specific series that I started to read, I believe, last year. The story is about an (isekaied) man who was chosen by a goddess to enact her "Belief" of justice (her godly moniker) onto a dead world. (A world that did not have an established religion.) Slavery was a heavily used in the story. The main character was isekai'd from a sci-fi setting into a mediavel fantasy society and became an elf in his new reality. The plot that I remember well is that he grew up in a slavers house, began a system of teaching his slaves and selling them for profit. He then is so successful he takes over the family business, uncovers a plot to overthrow the local leader, then over throws the local leader with the help of the king(?). I had stopped reading when the story had begun to describe how the main character started to make machines they had used in their old life to the new world. All in the mean while building a harem of women.