Yea I forgot most of the files with last commit, here's the actual thing

Author: TPGamesNL

src/main/java/com/btk5h/skriptmirror/skript/custom/event/BukkitCustomEvent.java

@@ -2,6 +2,7 @@
 
 import ch.njol.skript.classes.ClassInfo;
 import ch.njol.skript.registrations.Classes;
+import org.bukkit.Bukkit;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 
@@ -23,6 +24,11 @@ public class BukkitCustomEvent extends Event {
   private final Map<String, Object> dataMap;
 
   public BukkitCustomEvent(String name) {
+    this(name, !Bukkit.isPrimaryThread());
+  }
+
+  public BukkitCustomEvent(String name, boolean isAsync) {
+    super(isAsync);
     this.name = name;
     this.eventValueMap = new HashMap<>();
     this.dataMap = new HashMap<>();

src/main/java/com/btk5h/skriptmirror/skript/custom/event/CustomEvent.java

@@ -13,12 +13,13 @@
 
 /**
  * This is the Skript event for all custom classes.
- * {@link #getLastCustomEvent()} returns the last instance of this class, which is used internally for determining
+ * {@link #getLastWhich()} ()} returns the last EventSyntaxInfo of the last custom event, which is used internally for determining
  * which event-values can be used in parse-time.
  */
 public class CustomEvent extends SkriptEvent {
 
-  private static CustomEvent lastCustomEvent;
+//  private static CustomEvent lastCustomEvent;
+  private static EventSyntaxInfo lastWhich;
 
   private EventSyntaxInfo which;
   private Expression<?>[] exprs;
@@ -42,7 +43,8 @@ public boolean init(Literal<?>[] args, int matchedPattern, SkriptParser.ParseRes
       return false;
     }
 
-    lastCustomEvent = this;
+//    lastCustomEvent = this;
+    lastWhich = which;
 
     Trigger parseHandler = CustomEventSection.parserHandlers.get(which);
 
@@ -83,8 +85,12 @@ public String toString(@Nullable Event e, boolean debug) {
     return which.getPattern();
   }
 
-  public static CustomEvent getLastCustomEvent() {
-    return lastCustomEvent;
+  public static EventSyntaxInfo getLastWhich() {
+    return lastWhich;
+  }
+
+  public static void setLastWhich(EventSyntaxInfo which) {
+    lastWhich = which;
   }
 
   public EventSyntaxInfo getWhich() {

src/main/java/com/btk5h/skriptmirror/skript/custom/event/CustomEventSection.java

@@ -11,7 +11,6 @@
 import com.btk5h.skriptmirror.skript.custom.CustomSyntaxSection;
 import com.btk5h.skriptmirror.skript.custom.SyntaxParseEvent;
 import com.btk5h.skriptmirror.util.SkriptUtil;
-import org.bukkit.Bukkit;
 
 import java.io.File;
 import java.lang.reflect.Field;
@@ -135,6 +134,7 @@ protected boolean init(Literal<?>[] args, int matchedPattern, SkriptParser.Parse
 
         if (key.equalsIgnoreCase("check")) {
           ScriptLoader.setCurrentEvent("custom event trigger", EventTriggerEvent.class);
+          CustomEvent.setLastWhich(whichInfo.get(0));
           List<TriggerItem> items = SkriptUtil.getItemsFromNode(sectionNode);
           whichInfo.forEach(which ->
             eventHandlers.put(which,

src/main/java/com/btk5h/skriptmirror/skript/custom/event/CustomEventUtils.java

@@ -11,13 +11,11 @@
 public class CustomEventUtils {
 
   /**
-   * @param customEvent The CustomEvent which is used
+   * @param which The EventSyntaxInfo that belongs to the used custom event
    * @param classInfo The used ClassInfo
    * @return whether the given CustomEvent supports the given ClassInfo as an event-value.
    */
-  public static boolean hasEventValue(CustomEvent customEvent, ClassInfo<?> classInfo) {
-    EventSyntaxInfo which = customEvent.getWhich();
-
+  public static boolean hasEventValue(EventSyntaxInfo which, ClassInfo<?> classInfo) {
     List<ClassInfo<?>> eventValueClassInfoList = CustomEventSection.eventValueTypes.get(which);
     if (eventValueClassInfoList == null)
       return false;
@@ -40,11 +38,11 @@ public static String getName(ClassInfo<?> classInfo) {
   }
 
   /**
-   * @param customEvent The CustomEvent which name is returned
-   * @return The defined name (identifier) of the given CustomEvent.
+   * @param which The EventSyntaxInfo that belongs to the used custom event
+   * @return The defined name (identifier) of the custom event from the given EventSyntaxInfo
    */
-  public static String getName(CustomEvent customEvent) {
-    return CustomEventSection.nameValues.get(customEvent.getWhich());
+  public static String getName(EventSyntaxInfo which) {
+    return CustomEventSection.nameValues.get(which);
   }
 
 }

src/main/java/com/btk5h/skriptmirror/skript/custom/event/EffCallCustomEvent.java

@@ -16,7 +16,7 @@
 public class EffCallCustomEvent extends Effect {
 
   static {
-    Skript.registerEffect(EffCallCustomEvent.class, "call custom event %string% [(with|using) [[event-]values] %-objects%] [(with|using) data %-objects%]");
+    Skript.registerEffect(EffCallCustomEvent.class, "call custom event %string% [(with|using) [[event-]values] %-objects%] [[and] [(with|using)] data %-objects%]");
   }
 
   private Expression<String> customEventName;
@@ -53,8 +53,6 @@ public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelaye
 
   @Override
   protected void execute(Event e) {
-    // TODO check for async custom event call
-
     BukkitCustomEvent bukkitCustomEvent = new BukkitCustomEvent(this.customEventName.getSingle(e));
 
     if (eventValueVarList != null)

src/main/java/com/btk5h/skriptmirror/skript/custom/event/ExprCustomEventValue.java

@@ -31,10 +31,10 @@ public ExprCustomEventValue() {
 
   @Override
   public boolean init(final Expression<?>[] exprs, final int matchedPattern, final Kleenean isDelayed, final SkriptParser.ParseResult parseResult) {
-    if (!ScriptLoader.isCurrentEvent(BukkitCustomEvent.class))
+    if (!ScriptLoader.isCurrentEvent(BukkitCustomEvent.class, EventTriggerEvent.class))
       return false;
-    CustomEvent customEvent = CustomEvent.getLastCustomEvent();
-    if (customEvent == null)
+    EventSyntaxInfo which = CustomEvent.getLastWhich();
+    if (which == null)
       return false;
 
     String stringClass = parseResult.regexes.get(0).group();
@@ -43,9 +43,9 @@ public boolean init(final Expression<?>[] exprs, final int matchedPattern, final
       return false;
     }
 
-    if (!CustomEventUtils.hasEventValue(customEvent, classInfo)) {
+    if (!CustomEventUtils.hasEventValue(which, classInfo)) {
       Skript.error("There is no " + CustomEventUtils.getName(classInfo) + " in the custom event " +
-        CustomEventUtils.getName(customEvent));
+        CustomEventUtils.getName(which));
       return false;
     }
 
@@ -55,9 +55,14 @@ public boolean init(final Expression<?>[] exprs, final int matchedPattern, final
   @SuppressWarnings("unchecked")
   @Override
   public T[] get(Event event) {
-    if (!(event instanceof BukkitCustomEvent))
+    if (!(event instanceof BukkitCustomEvent || event instanceof EventTriggerEvent))
       return null;
-    BukkitCustomEvent bukkitCustomEvent = (BukkitCustomEvent) event;
+    BukkitCustomEvent bukkitCustomEvent;
+    if (event instanceof BukkitCustomEvent) {
+      bukkitCustomEvent = (BukkitCustomEvent) event;
+    } else {
+      bukkitCustomEvent = (BukkitCustomEvent) ((EventTriggerEvent) event).getEvent();
+    }
 
     T[] tArray = (T[]) Array.newInstance(classInfo.getC(), 1);
     tArray[0] = (T) bukkitCustomEvent.getEventValue(classInfo);

src/main/java/com/btk5h/skriptmirror/skript/custom/event/ExprEventData.java

@@ -0,0 +1,71 @@
+package com.btk5h.skriptmirror.skript.custom.event;
+
+import ch.njol.skript.ScriptLoader;
+import ch.njol.skript.Skript;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.ExpressionType;
+import ch.njol.skript.lang.SkriptParser;
+import ch.njol.skript.lang.util.SimpleExpression;
+import ch.njol.util.Kleenean;
+import com.btk5h.skriptmirror.util.SkriptUtil;
+import org.bukkit.event.Event;
+import org.eclipse.jdt.annotation.Nullable;
+
+import java.util.ArrayList;
+
+public class ExprEventData extends SimpleExpression<Object> {
+
+  static {
+    Skript.registerExpression(ExprEventData.class, Object.class, ExpressionType.COMBINED, "[extra] [event[-]] data %strings%");
+  }
+
+  private Expression<String> dataIndex;
+
+  @Override
+  public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, SkriptParser.ParseResult parseResult) {
+    if (!ScriptLoader.isCurrentEvent(BukkitCustomEvent.class, EventTriggerEvent.class)) {
+      Skript.error("This expression can only be used in a custom event");
+      return false;
+    }
+    dataIndex = SkriptUtil.defendExpression(exprs[0]);
+    return true;
+  }
+
+  @Nullable
+  @Override
+  protected Object[] get(Event e) {
+    BukkitCustomEvent bukkitCustomEvent;
+    if (e instanceof BukkitCustomEvent) {
+      bukkitCustomEvent = (BukkitCustomEvent) e;
+    } else {
+      bukkitCustomEvent = (BukkitCustomEvent) ((EventTriggerEvent) e).getEvent();
+    }
+
+    if (dataIndex.isSingle()) {
+      Object data = bukkitCustomEvent.getData(dataIndex.getSingle(e));
+      return new Object[] {data};
+    } else {
+      ArrayList<Object> arrayList = new ArrayList<>();
+      for (String index : dataIndex.getArray(e)) {
+        arrayList.add(bukkitCustomEvent.getData(index));
+      }
+      return arrayList.toArray();
+    }
+  }
+
+  @Override
+  public boolean isSingle() {
+    return dataIndex.isSingle();
+  }
+
+  @Override
+  public Class<?> getReturnType() {
+    return Object.class;
+  }
+
+  @Override
+  public String toString(@Nullable Event e, boolean debug) {
+    return "event data";
+  }
+
+}

src/main/java/com/btk5h/skriptmirror/skript/custom/event/ExprReplacedEventValue.java

@@ -28,8 +28,14 @@ public ExprReplacedEventValue(EventValueExpression<T> original) {
   @Override
   @Nullable
   protected T[] get(final Event e) {
-    if (e instanceof BukkitCustomEvent) {
-      BukkitCustomEvent bukkitCustomEvent = (BukkitCustomEvent) e;
+    if (e instanceof BukkitCustomEvent || e instanceof EventTriggerEvent) {
+      BukkitCustomEvent bukkitCustomEvent;
+      if (e instanceof BukkitCustomEvent) {
+        bukkitCustomEvent = (BukkitCustomEvent) e;
+      } else {
+        bukkitCustomEvent = (BukkitCustomEvent) ((EventTriggerEvent) e).getEvent();
+      }
+
       Class<?> valueClass = original.getReturnType();
 
       T[] tArray = (T[]) Array.newInstance(valueClass, 1);
@@ -43,10 +49,10 @@ protected T[] get(final Event e) {
   @SuppressWarnings("null")
   @Override
   public boolean init() {
-    if (ScriptLoader.isCurrentEvent(BukkitCustomEvent.class)) {
-      CustomEvent customEvent = CustomEvent.getLastCustomEvent();
+    if (ScriptLoader.isCurrentEvent(BukkitCustomEvent.class, EventTriggerEvent.class)) {
+      EventSyntaxInfo which = CustomEvent.getLastWhich();
       ClassInfo<?> classInfo = Classes.getSuperClassInfo(getReturnType());
-      return CustomEventUtils.hasEventValue(customEvent, classInfo);
+      return CustomEventUtils.hasEventValue(which, classInfo);
     } else {
       return original.init();
     }