EnhancedPropertyPattern.cs

using System;
using System.Collections.Generic;

var heroes = new List<IHero>
{
    new Hero("Homelander", new(true, true)),
    new Hero("Stormfront", new(true, false)),
};

// Old: if (heroes[0] is Hero { Flying: { CanFlyInSpace: true } })
if (heroes[0] is Hero { Flying.CanFlyInSpace: true })
{
    Console.WriteLine("Hero can fly on earth");
}

class Flying
{
    public bool CanFlyOnEarth { get; set; }
    public bool CanFlyInSpace { get; set; }
    public Flying(bool canFlyOnEarth, bool canFlyInSpace)
        => (CanFlyOnEarth, CanFlyInSpace) = (canFlyOnEarth, canFlyInSpace);
}

interface IHero { }
class Hero : IHero
{
    public string Name;
    public Flying Flying;
    public Hero(string name, Flying flying)
        => (Name, Flying) = (name, flying);
}