I'm not a native speaker of English, as you might have already noticed, but it's never posed a problem for my speaking or writing in English, since growing up in a city bordering the United States actually makes it an everyday thing. But when it comes to the 'natural convention' terms, I still have difficulties in both understanding and expressing them.
Such is the case of the 'Hardy Nature', or 'Hardy Personality' (by the means of this comic) I'm trying to define for my Croconaw. That's the main reason he hasn't really spoken any dialogue other than a 'yesh'. I have no idea what Hardy refers to, and its official translation 'Fuerte', as well as its being a Neutral Nature, doesn't really tell me what it is all about.
I did some Google research, of course, but I only have interpretations on the information I read, rather than a clear definition.

I interpreted, AND PLEASE CORRECT ME IF I'M WRONG, that a person with such a personality is kind of that 'Regular Person' who doesn't really stand out in the crowd and it's easy to get along with because they simply have no strong personality traits. In other words, they are people who, like, are not very smart - just enough to carry out their daily chores, and they have regular jobs where they don't have leading positions mostly because they don't have higher aspirations and work just fine being told what to do without feeling overwhelmed or expressing it openly if they were uncomfortable at any given situation. They are also not very creative, nor do they especially appreciate any form of art - like, they are completely ok hanging a typical painting of apples in the kitchen and listening to whatever music is 'hot' on the radio. They also have positive traits, since I believe they are not that kind of stay-at-home people. They practice sports, but not at a competitive level - like having a routine of jogging or playing basketball with their friends just to hang out, and maybe like going out dancing and drinking just for fun - without being great dancers or hardcore drinkers. Socially, they have long-lasting friendships and relationships in general, but these are not the 'deep' kind-of-level friendships because they are neither emotionally or intellectually deep, but are definitely the kind of people that can keep a marriage for decades - even until they die - perhaps because there are not many problems around them (and they also don't CREATE problems). Talking about intellect, they could be the kind of people who gets impressed by those cliché inspirational quotes with sunset/forest/beach backgrounds that are so common on social media nowadays, and they often share it on their facebook walls without giving a second read or a second thought on what the quote means. They do not need a lot to be happy. They are happy most of the time.

If there's a native speaker here, please help me. I want my Croconaw to start having some dialogue.