If you put all your instances of the Wizard class in an array, you can pick one by indexing that array; that would result in translating an integer number (zero-based) into one of a range of pre-instantiated wizards, like so:
Wizard[] wizards=new Wizard[10];
wizards[0]=new Wizard(...);
...
wizards[9]=new Wizard(...);
int myWizIndex=4;
Wizard myWizard=wizards[myWizIndex];
...
FYI: if you don't know the number of wizards you're going to have (you might create them dynamically) and/or if their integer indexes aren't necessarily a continuous and zero-based range, you could also use a
Dictionary<int,Wizard>
(that is a more advanced topic!).
:)