Choose 2 fighters and they fight each other to death

Coliseum

internal class Program
{
    public static void Main()
    {
        UserInterface userInterface = new();
        userInterface.MainMenu();
    }
}

class UserInterface
{
    private bool _isPlaying = true;

    public void MainMenu()
    {
        while (_isPlaying)
        {
            Console.Clear();
            Console.WriteLine("Press Space or Enter to Start a Game.\nPress any other button to exit.\n");

            if (char.IsWhiteSpace(Console.ReadKey().KeyChar))
                StartGame();
            else
                ExitApp();
        }
    }

    private void StartGame()
    {
        Character hero;
        Character enemy;
        Colliseum colliseum = new();

        Console.WriteLine("Pick a hero character.\n");
        hero = colliseum.PickHero();

        Console.WriteLine("Pick an enemy character.\n");
        enemy = colliseum.PickHero();

        colliseum.StartFight(hero, enemy);

        Console.WriteLine("\n\nPress any key to return to Main Menu");
        Console.ReadKey();
    }

    private void ExitApp()
    {
        Console.WriteLine("Good bye!");
        _isPlaying = false;
    }
}

class Colliseum
{
    readonly List<Character> _characters = new();

    public Colliseum()
    {
        CreateHeroes();
    }

    public Character PickHero()
    {
        int index;
        Character character;

        ShowHeroes();
        Console.Write("\nEnter number of a character: ");

        while (int.TryParse(Console.ReadLine(), out index) == false || _characters.Count < index || index <= 0)
        {
            Console.WriteLine("Incorrect enter! Try again!");
        }

        character = _characters[--index];
        _characters.RemoveAt(index);
        Console.Clear();

        return character;
    }

    public void ShowHeroes()
    {
        foreach (Character character in _characters)
        {
            Console.Write(_characters.IndexOf(character) + 1 + ". ");
            character.ShowStats();
            Console.WriteLine();
        }
    }

    public void StartFight(Character hero1, Character hero2)
    {
        string dividingLine = new('-', 50);

        Console.WriteLine("Press any key to start fight!");
        Console.ReadKey();
        Console.Clear();

        hero1.ShowReplic();
        Console.WriteLine();
        hero2.ShowReplic();

        while (hero1.IsAlive && hero2.IsAlive)
        {
            Console.WriteLine(dividingLine);

            Console.WriteLine($"Round {hero1.Step + 1}:\n");
            hero1.Attack(hero2);
            hero2.Attack(hero1);

            Console.WriteLine("\n" + dividingLine);

            hero1.ShowStats();
            Console.WriteLine();
            hero2.ShowStats();

            Console.ReadKey();
            Console.Clear();
        }

        ShowFightResult(hero1, hero2);
    }

    private void ShowFightResult(Character hero1, Character hero2)
    {
        Console.WriteLine(new string('#', 50));

        if (hero1.IsAlive)
            Console.WriteLine($"{hero1.Name} is a winner\n");
        else if (hero2.IsAlive)
            Console.WriteLine($"{hero2.Name} is a winner\n");
        else
            Console.WriteLine("It's a draw!\n");

        hero1.ShowStats();
        Console.WriteLine();
        hero2.ShowStats();
    }

    private void CreateHeroes()
    {
        _characters.Clear();
        _characters.Add(new Warrior(750, 40, 40));
        _characters.Add(new Priest(500, 20, 50));
        _characters.Add(new Mage(550, 25, 35));
        _characters.Add(new Rogue(650, 25, 35));
        _characters.Add(new Paladin(900, 30, 20));
    }
}

abstract class Character
{
    private protected int _health;

    public Character(int health, int damage, string name)
    {
        Step = 0;
        Name = name;
        Damage = damage;
        MaxHealth = health;
        _health = health;
    }

    public string Name { get; private set; }
    public int Step { get; private set; }
    public int Damage { get; private set; }
    public int MaxHealth { get; private set; }
    public bool IsAlive { get => _health > 0; }

    public void Attack(Character enemy)
    {
        Step++;
        Console.WriteLine($"{Name} deals {enemy.Name} {Damage} damage.");
        enemy._health -= Damage;
        UseSkill(enemy);
    }

    public void TakeDamage(int damage)
    {
        _health -= damage;
    }

    public virtual void ShowReplic()
    {
        Console.Write($"I am {Name}. \n");
    }

    public virtual void ShowStats()
    {
        Console.Write($"Name: {Name}, Health: {_health}, Damage: {Damage}");
    }

    private protected virtual void UseSkill(Character enemy) { }
}

class Warrior : Character
{
    private int _armor;

    public Warrior(int health, int damage, int skillPower, string name = "Warrior") : base(health, damage, name)
    {
        _armor = skillPower;
    }

    public override void ShowReplic()
    {
        base.ShowReplic();
        Console.WriteLine($"I will destroy you!\n");
    }

    public override void ShowStats()
    {
        base.ShowStats();
        Console.Write($", Armor: {_armor}.");
    }

    private protected override void UseSkill(Character enemy)
    {
        UseArmor(enemy);
    }

    private void UseArmor(Character enemy)
    {
        if (_armor == 0)
        {
            return;
        }
        else
        {
            _armor -= enemy.Damage;

            if (_armor < 0)
            {
                _health += enemy.Damage - _armor;
                _armor = 0;
                Console.WriteLine($"({Name}) Armor is destroyed!");
            }
            else
            {
                Console.WriteLine($"({Name}) Armor blocked all the damage!");
                _health += enemy.Damage;
            }
        }
    }
}

class Priest : Character
{
    private int _mana;
    private readonly int _maxMana;
    private readonly int _skillManaValue;
    private readonly int _healPower;
    private readonly int _manaRecovery;

    public Priest(int health, int damage, int skillPower, string name = "Priest") : base(health, damage, name)
    {
        _skillManaValue = 10;
        _healPower = 40;
        _manaRecovery = 5;
        _mana = skillPower;
        _maxMana = skillPower;
    }

    public override void ShowReplic()
    {
        base.ShowReplic();
        Console.WriteLine($"I won't let you harm others!\n");
    }

    public override void ShowStats()
    {
        base.ShowStats();
        Console.Write($", Mana: {_mana}.");
    }

    private protected override void UseSkill(Character enemy)
    {
        ManaRecovery();
        Heal();
    }

    private void Heal()
    {
        if (_mana > _skillManaValue)
        {
            _health += _healPower;
            _mana -= _skillManaValue;
            Console.WriteLine($"({Name}) Uses healing skill (+{_healPower} HP)!");
        }

        _health = _health > MaxHealth ? MaxHealth : _health;
    }

    private void ManaRecovery()
    {
        _mana = _mana + _manaRecovery >= _maxMana ? _maxMana : _mana + _manaRecovery;
        Console.WriteLine($"({Name}) Rstores {_manaRecovery} points of mana");
    }
}

class Mage : Character
{
    private int _skillCounter;
    private readonly int _fireBallDamage;
    private readonly int _damageSkillStep;

    public Mage(int health, int damage, int skillPower, string name = "Mage") : base(health, damage, name)
    {
        _damageSkillStep = 2;
        _fireBallDamage = skillPower;
    }

    public override void ShowReplic()
    {
        base.ShowReplic();
        Console.WriteLine($"I will burn you to ashes!\n");
    }

    public override void ShowStats()
    {
        base.ShowStats();
        Console.Write($", Skill name: Fire Ball, Used times: {_skillCounter}.");
    }

    private protected override void UseSkill(Character enemy)
    {
        UseFireBall(enemy);
    }

    private void UseFireBall(Character enemy)
    {
        if (Step % _damageSkillStep == 0)
        {
            Console.WriteLine($"({Name}) Uses FireBall and deals {_fireBallDamage} damage to {enemy.Name}");
            enemy.TakeDamage(_fireBallDamage);
            _skillCounter++;
        }
    }
}

class Rogue : Character
{
    private readonly float _attackSpeed;
    private readonly float _speedRate;

    public Rogue(int health, int damage, int skillPower, string name = "Rogue") : base(health, damage, name)
    {
        _speedRate = 0.01f;
        _attackSpeed = (float)skillPower * _speedRate;
    }

    public override void ShowReplic()
    {
        base.ShowReplic();
        Console.WriteLine($"I will kill you silently\n");
    }

    public override void ShowStats()
    {
        base.ShowStats();
        Console.Write($", Attack speed: {_attackSpeed}.");
    }

    private protected override void UseSkill(Character enemy)
    {
        enemy.TakeDamage(UseFlurryOfBlows());
        Console.WriteLine($"{Name} deals extra {(int)(_attackSpeed * Damage)} damage to {enemy.Name}");
    }

    private int UseFlurryOfBlows()
    {
        return (int)(_attackSpeed * Damage);
    }
}

class Paladin : Character
{
    private int _armor;
    private int _mana;
    private int _skillCounter;
    private readonly int _lightDamage;
    private readonly int _skillManaCost;
    private readonly int _skillHealing;
    private readonly float _damageSkillRatio;
    private readonly int _damageSkillStep;

    public Paladin(int health, int damage, int skillPower, string name = "Paladin") : base(health, damage, name)
    {
        _skillManaCost = 5;
        _skillHealing = 5;
        _damageSkillRatio = 1.5f;
        _damageSkillStep = 3;

        _armor = skillPower;
        _mana = skillPower;
        _lightDamage = (int)(skillPower * _damageSkillRatio);
    }

    public override void ShowReplic()
    {
        base.ShowReplic();
        Console.WriteLine($"I will save my people!\n");
    }

    public override void ShowStats()
    {
        base.ShowStats();
        Console.Write($", Armor: {_armor}, Mana: {_mana}, ");
        Console.Write($"Light attack used: {_skillCounter} times.");
    }

    private protected override void UseSkill(Character enemy)
    {
        UseArmor(enemy);
        Heal();
        UsePillarOfLight(enemy);
    }

    private void UseArmor(Character enemy)
    {
        if (_armor > 0)
        {
            _armor -= enemy.Damage;

            if (_armor < 0)
            {
                _health += enemy.Damage - _armor;
                _armor = 0;
                Console.WriteLine($"({Name}) Armor is destroyed!");
            }
            else
            {
                Console.WriteLine($"({Name}) Armor blocked all the damage!");
                _health += enemy.Damage;
            }
        }
    }

    private void Heal()
    {
        if (_mana >= _skillManaCost)
        {
            Console.WriteLine($"({Name}) Uses healing skill (+{_skillHealing} HP)!");
            _health += _skillHealing;
            _mana -= _skillManaCost;
        }

        _health = _health > MaxHealth ? MaxHealth : _health;
    }

    private void UsePillarOfLight(Character enemy)
    {
        if (Step % _damageSkillStep == 0 && _mana >= _skillManaCost)
        {
            _skillCounter++;
            enemy.TakeDamage(_lightDamage);
            _mana -= _skillManaCost;
            Console.WriteLine($"{Name} uses Light Attack! Deals {_lightDamage} danmage to {enemy.Name}");
        }
    }
}