I'm not 100% sure what the problem your running into is aside from accessing the derived classes data.
You could have character have a virtual method called DoAttack() where each derived class can override it to do whatever they have todo. Another approach to the problem is to use composition and instead of creating bladewarrior, fistwarrior, drunkenwarrior, you could have a single class called GameMonster (or w.e) which would contain a pointer to another class that has more information on the type of monster it is.
This article should help you. http://gameprogrammingpatterns.com/type-object.html
The cool part about doing it that was is you can have all your different monsters in an xml file and modify attributes without having to recompile. You can also make sub-monster types without having to specify every attribute and instead have it "inherit" from it's parent monster type.
EDIT: Since it's C# that you're using, you don't have to worry about pointers. Classes are passed by reference so you can just set your monsters to have w.e monster type you want.
e.g. Monster m = new Monster(); //You could do it the way the article shows as well
The only thing is that if you have custom attack patterns or something you would need to do a litle more work. Maybe something like m.SetBehavior(new WarriorBehavior(WarriorStyle.Fist)); Just an idea, haven't gotten up to that yet in my project