Unity Simple Beastiary With Saving / Loading Built In

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;

[System.Serializable]
public class Beastiary : MonoBehaviour {


                //Follow me on twitter @RKSlither_Yt  / @ThePinkertonCo
                //youtube @RKSlither

    private static Beastiary instance;

    public List<MonstersBeastiaryData> monsters = new List<MonstersBeastiaryData>();

    public Button[] beastiarySelectables;

    public Image beastiarySprite;

    public Text[] beastiarySelectableNames;

    public Text beastiaryMainName;

    public Text beastiaryLocation;

    private readonly string beastiaryImageLoadPath = "Monsters/";

    private readonly string saveDirectory = "/BeastiaryData/";
    private readonly string saveFile = "Beastiary.unitySaveData";

    private void Awake()
    {
        instance = GetComponent<Beastiary>();
        if(!Directory.Exists(Application.persistentDataPath + saveDirectory))
        {
            Directory.CreateDirectory(Application.persistentDataPath + saveDirectory);
        }
        if(File.Exists(Application.persistentDataPath + saveDirectory + saveFile))
        {
            LoadBeastiaryData();
        }
    }

    public static void UnlockBeastiary(int index)
    {
        for (int i = 0; i < instance.monsters.Count; i++)
        {
            if(i < instance.monsters.Count)
            {
                if(i == index)
                {
                    if (!instance.monsters[index].unlockedData)
                    {
                        instance.monsters[index].unlockedData = true;
                        UpdateBeastiary();
                    }
                    else
                    {
                        return;
                    }
                }
            }else if( i >= instance.monsters.Count)
            {
                return;
            }
        }
    }

    public static void UpdateBeastiary()
    {
        for (int i = 0; i < instance.beastiarySelectables.Length; i++)
        {
            int temp = i; //you need this otherwise it will assign each
            //button the same int index cause unity blows in this instance
            if( i < instance.monsters.Count)
            {
                if (instance.monsters[i].unlockedData)
                {
                    instance.beastiarySelectableNames[i].text = instance.monsters[i].monsterName;
                    instance.beastiarySelectables[i].onClick.RemoveAllListeners();
                    instance.beastiarySelectables[i].onClick.AddListener(() => instance.ShowBeastData(temp));
                    instance.beastiarySelectables[i].interactable = true;//always update the button last incase it loads wrong
                }else if (!instance.monsters[i].unlockedData)
                {
                    instance.beastiarySelectableNames[i].text = "?????????";
                    instance.beastiarySelectables[i].onClick.RemoveAllListeners();
                    instance.beastiarySelectables[i].interactable = false;//always update the button last incase it loads wrong
                }

            }
            else if(i >= instance.monsters.Count && i < instance.beastiarySelectables.Length)
            {
                instance.beastiarySelectables[i].interactable = false;
                instance.beastiarySelectableNames[i].text = "?????????";
            }else if(i >= instance.monsters.Count && i < instance.beastiarySelectables.Length)
            {
                instance.beastiarySelectables[i].interactable = false;
                instance.beastiarySelectableNames[i].text = "?????????";
                instance.beastiarySprite.sprite = (Sprite)Resources.Load<Sprite>(instance.beastiaryImageLoadPath + "Unknown") as Sprite;
                instance.beastiaryLocation.text = "?????????";
            }
        }
    }

    private void ShowBeastData(int index)
    {
        if(instance.monsters.Count >= index)
        {
            instance.beastiaryMainName.text = instance.monsters[index].monsterName;
            instance.beastiarySprite.sprite = (Sprite)Resources.Load<Sprite>(instance.beastiaryImageLoadPath + instance.monsters[index].monsterSpriteIndex) as Sprite;
            instance.beastiaryLocation.text = instance.monsters[index].monsterLocation;
        }
        else
        {
            return;
        }
    }

    public static void SaveBeastiaryData()
    {
        BinaryFormatter bf = new BinaryFormatter();

        if(!File.Exists(Application.persistentDataPath + instance.saveDirectory + instance.saveFile))
        {
            FileStream file = File.Create(Application.persistentDataPath + instance.saveDirectory + instance.saveFile);

            SavedBeastiaryData saveData = new SavedBeastiaryData();
            saveData.beastiaryMonsterData = instance.monsters;
            bf.Serialize(file, saveData);
            file.Close();
        }else if (File.Exists(Application.persistentDataPath + instance.saveDirectory + instance.saveFile))
        {
            FileStream file = File.Open(Application.persistentDataPath + instance.saveDirectory + instance.saveFile,FileMode.Open);
            SavedBeastiaryData saveData =   (SavedBeastiaryData)bf.Deserialize(file) as SavedBeastiaryData;
            saveData.beastiaryMonsterData = instance.monsters;
            bf.Serialize(file, saveData);
            file.Close();
        }
    }

    public static void LoadBeastiaryData()
    {
        BinaryFormatter bf = new BinaryFormatter();

        if (!File.Exists(Application.persistentDataPath + instance.saveDirectory + instance.saveFile))
        {
            //set your beastiary defaults here like a free unlock for the game start or a tutorial
            //that gives a free unlock
            return;
        }
        else if (File.Exists(Application.persistentDataPath + instance.saveDirectory + instance.saveFile))
        {
            FileStream file = File.Open(Application.persistentDataPath + instance.saveDirectory + instance.saveFile, FileMode.Open);
            SavedBeastiaryData saveData = (SavedBeastiaryData)bf.Deserialize(file) as SavedBeastiaryData;
            instance.monsters = saveData.beastiaryMonsterData;
            file.Close();
            UpdateBeastiary();
        }
    }
}

[System.Serializable]
public class MonstersBeastiaryData
{
    public string monsterName;
    public string monsterLocation;
    public string monsterSpriteIndex;
    public bool unlockedData;

}


[System.Serializable]
public class SavedBeastiaryData
{
    public List<MonstersBeastiaryData> beastiaryMonsterData = new List<MonstersBeastiaryData>();

}