I am making a small program for myself on a video game. The issue is that it reads certain objects as not defined when it says the errors in the page. 

```
$(document).ready(function(){
        //A roster for all character choices.
        var roster = {
            Riven:{name: "Riven", rival: Jax, rival2: Pantheon}, 
            Pantheon:{name: "Pantheon", rival: Olaf, rival2: Darius},
            Veigar:{name: "Veigar", rival: Akali, rival2: Fizz},
            Olaf:{name: "Olaf", rival: Kayle, rival2: Kennen},
            Jax:{name: "Jax", rival: Malphite, rival2: Pantheon},
            Akali:{name: "Akali", rival: Garen, rival2: LeeSin},
            Malphite:{}, 
            Darius:{}, 
            LeeSin:{}, 
            Garen:{}, 
            Kayle:{},
            Fizz:{},
        };

```

It says the object Darius is not defined in Pantheon's object or any time I reference Darius after this block of code. However, the Olaf, Akali, and anyone that had the full object property list are defined. I tried putting in those properties in the objects being read as not defined, but that does not work. I'm new to JavaScript, and I have no clue what to do. If it is relevant, I am calling jQuery library in the script just before this in my HTML code.