diff --git a/src/main/java/me/night/nullvalkyrie/commands/ArmorCommand.java b/src/main/java/me/night/nullvalkyrie/commands/ArmorCommand.java
index 220d625..7bebfc2 100644
--- a/src/main/java/me/night/nullvalkyrie/commands/ArmorCommand.java
+++ b/src/main/java/me/night/nullvalkyrie/commands/ArmorCommand.java
@@ -23,6 +23,7 @@ public class ArmorCommand extends Command {
         if (sender instanceof Player player) {
             ItemStack helmet = new ItemStack(Material.LEATHER_HELMET);
             LeatherArmorMeta helmetdata = (LeatherArmorMeta) helmet.getItemMeta();
+            if (helmetdata == null) return;
             helmetdata.setDisplayName(net.md_5.bungee.api.ChatColor.of("#ff23ff") + "Angeles Helmet");
             helmetdata.setColor(org.bukkit.Color.fromRGB(2, 2, 58));
             helmetdata.setUnbreakable(true);
@@ -31,6 +32,7 @@ public class ArmorCommand extends Command {
 
             ItemStack cp = new ItemStack(Material.LEATHER_CHESTPLATE);
             LeatherArmorMeta cpdata = (LeatherArmorMeta) cp.getItemMeta();
+            if (cpdata == null) return;
             cpdata.setDisplayName(net.md_5.bungee.api.ChatColor.of("#ff23ff") + "Angeles Chestplate");
             cpdata.setColor(org.bukkit.Color.fromRGB(2, 2, 58));
             cpdata.setUnbreakable(true);
@@ -39,6 +41,7 @@ public class ArmorCommand extends Command {
 
             ItemStack leg = new ItemStack(Material.LEATHER_LEGGINGS);
             LeatherArmorMeta legdata = (LeatherArmorMeta) leg.getItemMeta();
+            if (legdata == null) return;
             legdata.setDisplayName(net.md_5.bungee.api.ChatColor.of("#ff23ff") + "Angeles Leggings");
             legdata.setColor(org.bukkit.Color.fromRGB(2, 2, 58));
             legdata.setUnbreakable(true);
@@ -47,6 +50,7 @@ public class ArmorCommand extends Command {
 
             ItemStack boot = new ItemStack(Material.LEATHER_BOOTS);
             LeatherArmorMeta bootdata = (LeatherArmorMeta) boot.getItemMeta();
+            if (bootdata == null) return;
             bootdata.setDisplayName(net.md_5.bungee.api.ChatColor.of("#ff23ff") + "Angeles Boots");
             bootdata.setColor(org.bukkit.Color.fromRGB(2, 2, 58));
             bootdata.setUnbreakable(true);
diff --git a/src/main/java/me/night/nullvalkyrie/commands/HologramCommand.java b/src/main/java/me/night/nullvalkyrie/commands/HologramCommand.java
index 3b4ace8..283942c 100644
--- a/src/main/java/me/night/nullvalkyrie/commands/HologramCommand.java
+++ b/src/main/java/me/night/nullvalkyrie/commands/HologramCommand.java
@@ -19,9 +19,8 @@ public class HologramCommand extends Command {
             String[] ar = new String[]{ChatColor.AQUA + "Hi", ChatColor.DARK_PURPLE + "What", ChatColor.GOLD + "Hello World"};
             Location location = player.getLocation();
             for (String line : ar) {
-                ArmorStand stand = location.getWorld().spawn(location.subtract(0, 0.3, 0), ArmorStand.class, armorStand -> {
-                    armorStand.setVisible(false);
-                });
+                ArmorStand stand = location.getWorld().spawn(location.subtract(0, 0.3, 0), ArmorStand.class);
+                stand.setVisible(false);
                 stand.setGravity(false);
                 stand.setInvulnerable(true);
                 stand.setCustomNameVisible(true);
diff --git a/src/main/java/me/night/nullvalkyrie/commands/VanishCommand.java b/src/main/java/me/night/nullvalkyrie/commands/VanishCommand.java
index c0fb3ce..cceb3c9 100644
--- a/src/main/java/me/night/nullvalkyrie/commands/VanishCommand.java
+++ b/src/main/java/me/night/nullvalkyrie/commands/VanishCommand.java
@@ -1,5 +1,6 @@
 package me.night.nullvalkyrie.commands;
 
+import me.night.nullvalkyrie.Main;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
@@ -22,13 +23,13 @@ public class VanishCommand extends Command {
             if (vanished.contains(player.getUniqueId())) {
                 vanished.remove(player.getUniqueId());
                 for (Player target : Bukkit.getOnlinePlayers()) {
-                    target.showPlayer(player);
+                    target.showPlayer(Main.getPlugin(Main.class), player);
                 }
                 player.sendMessage(ChatColor.GREEN + "You are now seen by people");
             } else {
                 vanished.add(player.getUniqueId());
                 for (Player target : Bukkit.getOnlinePlayers()) {
-                    target.hidePlayer(player);
+                    target.hidePlayer(Main.getPlugin(Main.class), player);
                 }
                 player.sendMessage(ChatColor.GREEN + "You are now vanished");
             }
diff --git a/src/main/java/me/night/nullvalkyrie/database/CustomWeaponsDataManager.java b/src/main/java/me/night/nullvalkyrie/database/CustomWeaponsDataManager.java
index 9e05221..970031f 100644
--- a/src/main/java/me/night/nullvalkyrie/database/CustomWeaponsDataManager.java
+++ b/src/main/java/me/night/nullvalkyrie/database/CustomWeaponsDataManager.java
@@ -27,7 +27,7 @@ public class CustomWeaponsDataManager {
                 abi.put("Name", ability.getString("Name"));
                 List<String> details = new ArrayList<>();
                 if (ability.get("Details") != null)
-                    for (String s : (List<String>) ability.get("Details")) details.add(s);
+                    details.addAll((List<String>) ability.get("Details"));
                 abi.put("Details", details);
                 for (String a : properties.keySet()) prop.put(a, properties.get(a));
                 lores.put("Ability", abi);
@@ -49,7 +49,7 @@ public class CustomWeaponsDataManager {
                 for (String i : ing.keySet())
                     ingredients.put(i, ing.getString(i));
                 List<String> shapes = new ArrayList<>();
-                if (recipe.get("Shapes") != null) for (String s : (List<String>) recipe.get("Shapes")) shapes.add(s);
+                if (recipe.get("Shapes") != null) shapes.addAll((List<String>) recipe.get("Shapes"));
                 recipes.put("Shape", shapes);
                 recipes.put("Amount", recipe.getInteger("Amount"));
                 recipes.put("Ingredients", ingredients);
@@ -83,7 +83,7 @@ public class CustomWeaponsDataManager {
                 abi.put("Name", ability.getString("Name"));
                 List<String> details = new ArrayList<>();
                 if (ability.get("Details") != null)
-                    for (String s : (List<String>) ability.get("Details")) details.add(s);
+                    details.addAll((List<String>) ability.get("Details"));
                 abi.put("Details", details);
                 for (String a : properties.keySet()) prop.put(a, properties.get(a));
                 lores.put("Ability", abi);
diff --git a/src/main/java/me/night/nullvalkyrie/database/MinerDataManager.java b/src/main/java/me/night/nullvalkyrie/database/MinerDataManager.java
index c18217b..d916d19 100644
--- a/src/main/java/me/night/nullvalkyrie/database/MinerDataManager.java
+++ b/src/main/java/me/night/nullvalkyrie/database/MinerDataManager.java
@@ -1,7 +1,6 @@
 package me.night.nullvalkyrie.database;
 
 import com.mongodb.client.MongoCursor;
-import com.mongodb.client.model.Filters;
 import me.night.nullvalkyrie.entities.miners.CryptoMiner;
 import org.bson.Document;
 import org.bson.conversions.Bson;
@@ -32,23 +31,19 @@ public class MinerDataManager {
     }
 
     public static long getLastClaim(long id) {
-        try (MongoCursor<Document> cursor = DatabaseManager.getMinersDB().find(Filters.eq("ID", id)).cursor()) {
-            while (cursor.hasNext()) {
-                Document doc = cursor.next();
-                for (String key : doc.keySet()) {
-                    if (key.equals("LastClaim")) return (long) doc.get(key);
-                }
+        Document doc = DatabaseManager.getMinersDB().find(new Document("ID", id)).first();
+        if (doc != null) {
+            for (String key : doc.keySet()) {
+                if (key.equals("LastClaim")) return (long) doc.get(key);
             }
         }
         return 0;
     }
 
     public static CryptoMiner getMiner(long id) {
-        try (MongoCursor<Document> cursor = DatabaseManager.getMinersDB().find(Filters.eq("ID", id)).cursor()) {
-            while (cursor.hasNext()) {
-                Document doc = cursor.next();
-                return new CryptoMiner(doc.getString("Name"), Material.matchMaterial(doc.getString("Material")), doc.getInteger("Level"), doc.getDouble("Rate"), doc.getLong("LastClaim"));
-            }
+        Document doc = DatabaseManager.getMinersDB().find(new Document("ID", id)).first();
+        if (doc != null) {
+            return new CryptoMiner(doc.getString("Name"), Material.matchMaterial(doc.getString("Material")), doc.getInteger("Level"), doc.getDouble("Rate"), doc.getLong("LastClaim"));
         }
         return null;
     }
diff --git a/src/main/java/me/night/nullvalkyrie/discord/DiscordClientManager.java b/src/main/java/me/night/nullvalkyrie/discord/DiscordClientManager.java
index 0916bc7..8247a06 100644
--- a/src/main/java/me/night/nullvalkyrie/discord/DiscordClientManager.java
+++ b/src/main/java/me/night/nullvalkyrie/discord/DiscordClientManager.java
@@ -9,7 +9,6 @@ import javax.security.auth.login.LoginException;
 
 
 public class DiscordClientManager {
-    private JDA jda;
 
     public DiscordClientManager() {
         register();
@@ -19,7 +18,7 @@ public class DiscordClientManager {
         JDABuilder builder = JDABuilder.createDefault(Main.env.get("DISCORD_TOKEN"));
         builder.setActivity(Activity.streaming("cath.exe", "https://www.youtube.com/watch?v=YSKDu1gKntY"));
         try {
-            jda = builder.build();
+            JDA jda = builder.build();
         } catch (LoginException e) {
             e.printStackTrace();
         }
diff --git a/src/main/java/me/night/nullvalkyrie/events/custom/InteractHologramEvent.java b/src/main/java/me/night/nullvalkyrie/events/custom/InteractHologramEvent.java
index 5b802ce..6d8e275 100644
--- a/src/main/java/me/night/nullvalkyrie/events/custom/InteractHologramEvent.java
+++ b/src/main/java/me/night/nullvalkyrie/events/custom/InteractHologramEvent.java
@@ -8,8 +8,8 @@ import org.bukkit.event.HandlerList;
 import org.jetbrains.annotations.NotNull;
 public class InteractHologramEvent extends Event implements Cancellable {
     private boolean isCancelled;
-    public Player player;
-    public ArmorStand hologram;
+    public final Player player;
+    public final ArmorStand hologram;
     private static final HandlerList HANDLERS = new HandlerList();
     public InteractHologramEvent(Player player, ArmorStand hologram) {
         this.player = player;
diff --git a/src/main/java/me/night/nullvalkyrie/events/listeners/CustomItemEvents.java b/src/main/java/me/night/nullvalkyrie/events/listeners/CustomItemEvents.java
index f429351..f672546 100644
--- a/src/main/java/me/night/nullvalkyrie/events/listeners/CustomItemEvents.java
+++ b/src/main/java/me/night/nullvalkyrie/events/listeners/CustomItemEvents.java
@@ -230,9 +230,8 @@ public class CustomItemEvents implements Listener {
 
     @EventHandler
     public void onDamage(EntityDamageByEntityEvent e) {
-        if (e.getEntity() instanceof Player) {
-            Player player = (Player) e.getEntity();
-//            if ((player.getHealth() - e.getDamage()) <= 0) {
+        if (e.getEntity() instanceof Player player) {
+            //            if ((player.getHealth() - e.getDamage()) <= 0) {
 //                e.setCancelled(true);
 //                Location loc = player.getWorld().getBlockAt(-3, 23, -3).getLocation();
 //                player.teleport(loc);
@@ -335,7 +334,7 @@ public class CustomItemEvents implements Listener {
         }
     }
 
-    ProtocolManager manager = ProtocolLibrary.getProtocolManager();
+    final ProtocolManager manager = ProtocolLibrary.getProtocolManager();
 
     public void sendBlockDamage(Player player, Block block) {
         Location location = block.getLocation();
diff --git a/src/main/java/me/night/nullvalkyrie/events/listeners/DamageEffectEvents.java b/src/main/java/me/night/nullvalkyrie/events/listeners/DamageEffectEvents.java
index b934040..d76848d 100644
--- a/src/main/java/me/night/nullvalkyrie/events/listeners/DamageEffectEvents.java
+++ b/src/main/java/me/night/nullvalkyrie/events/listeners/DamageEffectEvents.java
@@ -18,7 +18,7 @@ import java.text.DecimalFormat;
 import java.util.*;
 
 public class DamageEffectEvents implements Listener {
-    public World world = Bukkit.getWorld("world");
+    public final World world = Bukkit.getWorld("world");
     public final Map<Entity, Integer> indicators = new HashMap<>();
     private final DecimalFormat formatter = new DecimalFormat("#");
 
diff --git a/src/main/java/me/night/nullvalkyrie/events/listeners/ServerEvents.java b/src/main/java/me/night/nullvalkyrie/events/listeners/ServerEvents.java
index 469f9c6..c37fbc6 100644
--- a/src/main/java/me/night/nullvalkyrie/events/listeners/ServerEvents.java
+++ b/src/main/java/me/night/nullvalkyrie/events/listeners/ServerEvents.java
@@ -15,8 +15,8 @@ import org.bukkit.event.weather.WeatherChangeEvent;
 import java.io.File;
 
 public class ServerEvents implements Listener {
-    public BossBar bossbar;
-    public PacketInjector injector;
+    public final BossBar bossbar;
+    public final PacketInjector injector;
     public ServerEvents() {
         bossbar = Bukkit.createBossBar(ChatColor.GOLD + "Kuudra", BarColor.RED, BarStyle.SEGMENTED_12);
         this.injector = new PacketInjector();
diff --git a/src/main/java/me/night/nullvalkyrie/items/CustomItemManager.java b/src/main/java/me/night/nullvalkyrie/items/CustomItemManager.java
index 2f79fce..2dabd7a 100644
--- a/src/main/java/me/night/nullvalkyrie/items/CustomItemManager.java
+++ b/src/main/java/me/night/nullvalkyrie/items/CustomItemManager.java
@@ -21,7 +21,7 @@ import java.util.*;
 import static me.night.nullvalkyrie.database.CustomWeaponsDataManager.getWeapon;
 
 public class CustomItemManager {
-    public static HashMap<String, NamespacedKey> keys = new HashMap<>();
+    public static final HashMap<String, NamespacedKey> keys = new HashMap<>();
 
     public static ItemStack produceItem(String itemName) {
         HashMap<String, Object> weapon = getWeapon(itemName);
diff --git a/src/main/java/me/night/nullvalkyrie/items/Pickaxe.java b/src/main/java/me/night/nullvalkyrie/items/Pickaxe.java
index abe63d8..e34be58 100644
--- a/src/main/java/me/night/nullvalkyrie/items/Pickaxe.java
+++ b/src/main/java/me/night/nullvalkyrie/items/Pickaxe.java
@@ -7,8 +7,8 @@ import org.bukkit.inventory.ItemStack;
 import java.util.HashMap;
 
 public class Pickaxe {
-    public ArrayListMultimap<Material, Material> multimap = ArrayListMultimap.create();
-    public HashMap<Material, Long> phases = new HashMap<>();
+    public final ArrayListMultimap<Material, Material> multimap = ArrayListMultimap.create();
+    public final HashMap<Material, Long> phases = new HashMap<>();
     private final ItemStack itemStack;
     public Pickaxe(ItemStack item) {
         multimap.put(Material.STONE_PICKAXE, Material.IRON_ORE); //put some blocks and pickaxe to mine
diff --git a/src/main/java/me/night/nullvalkyrie/ui/inventory/InventoryListener.java b/src/main/java/me/night/nullvalkyrie/ui/inventory/InventoryListener.java
index 096448b..6aa6475 100644
--- a/src/main/java/me/night/nullvalkyrie/ui/inventory/InventoryListener.java
+++ b/src/main/java/me/night/nullvalkyrie/ui/inventory/InventoryListener.java
@@ -21,6 +21,7 @@ public class InventoryListener implements Listener {
                     player.sendMessage(ChatColor.RED + "又做兵 抵死");
                     break;
                 case 22:
+                    player.teleport(player.getWorld().getSpawnLocation());
                     break;
                 case 24:
                     player.closeInventory();
diff --git a/src/main/java/me/night/nullvalkyrie/ui/player/NameTagManager.java b/src/main/java/me/night/nullvalkyrie/ui/player/NameTagManager.java
index 2b5c187..edb8cb5 100644
--- a/src/main/java/me/night/nullvalkyrie/ui/player/NameTagManager.java
+++ b/src/main/java/me/night/nullvalkyrie/ui/player/NameTagManager.java
@@ -6,6 +6,8 @@ import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.bukkit.scoreboard.*;
 
+import java.util.Objects;
+
 public class NameTagManager {
     public void setNametags(Player player) {
         Scoreboard newScoreboard = Bukkit.getScoreboardManager().getNewScoreboard();
@@ -27,8 +29,7 @@ public class NameTagManager {
     public void newTag(Player player) {
         Rank rank = RankDataManager.getRank(player.getUniqueId());
         for (Player target : Bukkit.getOnlinePlayers()) {
-            if (rank == null) target.getScoreboard().getTeam(Rank.ROOKIE.name()).addEntry(player.getName());
-            else target.getScoreboard().getTeam(rank.name()).addEntry(player.getName());
+            target.getScoreboard().getTeam(Objects.requireNonNullElse(rank, Rank.ROOKIE).name()).addEntry(player.getName());
         }
     }