Leonardo was pretty similar to all the other Nascent Soul Realm cultivators the twins got for the sect, people who cultivated slowly and didn't get much of a good life. Simply put, people who didn't mind betting on joining the System Sect regardless of how shady the proposal seemed at first.
However, he was someone with an odd affinity, an extremely odd one at that, iron. Yes, Leonardo could somehow manipulate iron to a certain extent, but only iron, the normal unimpressive one. With that, it could be called a branch of Earth Element Affinity. Back in Sunkan Planet, the twins also heard about a person with Bronze affinity.
