using System;

class Evil
{
    public new Type GetType() => typeof(SonOfEvil);
}

class SonOfEvil : Evil {}
class DaughterOfEvil : Evil {}

public class Test
{
    public static void Main()
    {
        Evil e = new DaughterOfEvil();
        if (e.GetType() == typeof(SonOfEvil))
            Console.WriteLine("похож на SonOfEvil");
    }
}