Program: 133846
Project: 133846
Buggy source:
@Override public void progress(){
  progressCounter++;
  if (player.isDead() || !player.isOnline()) {
    remove();
    return;
  }
 else   if (currentLoc != null && GeneralMethods.isRegionProtectedFromBuild(this,currentLoc)) {
    remove();
    return;
  }
  if (abilityName.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      state=AbilityState.TWISTER_MOVING;
      direction=player.getEyeLocation().getDirection().clone().normalize();
      direction.setY(0);
      origin=player.getLocation().add(direction.clone().multiply(2));
      destination=player.getLocation().add(direction.clone().multiply(range));
      currentLoc=origin.clone();
    }
    if (origin.distanceSquared(currentLoc) < origin.distanceSquared(destination) && state == AbilityState.TWISTER_MOVING) {
      currentLoc.add(direction.clone().multiply(speed));
    }
 else     if (state == AbilityState.TWISTER_MOVING) {
      state=AbilityState.TWISTER_STATIONARY;
      time=System.currentTimeMillis();
    }
 else     if (System.currentTimeMillis() - time >= twisterRemoveDelay) {
      remove();
      return;
    }
 else     if (GeneralMethods.isRegionProtectedFromBuild(this,currentLoc)) {
      remove();
      return;
    }
    Block topBlock=GeneralMethods.getTopBlock(currentLoc,3,-3);
    if (topBlock == null) {
      remove();
      return;
    }
    currentLoc.setY(topBlock.getLocation().getY());
    double height=twisterHeight;
    double radius=twisterRadius;
    for (double y=0; y < height; y+=twisterHeightParticles) {
      double animRadius=((radius / height) * y);
      for (double i=-180; i <= 180; i+=twisterDegreeParticles) {
        Vector animDir=GeneralMethods.rotateXZ(new Vector(1,0,1),i);
        Location animLoc=currentLoc.clone().add(animDir.multiply(animRadius));
        animLoc.add(0,y,0);
        playAirbendingParticles(animLoc,1,0,0,0);
      }
    }
    playAirbendingSound(currentLoc);
    for (int i=0; i < height; i+=3) {
      for (      Entity entity : GeneralMethods.getEntitiesAroundPoint(currentLoc.clone().add(0,i,0),radius * 0.75)) {
        if (!affectedEntities.contains(entity) && !entity.equals(player)) {
          affectedEntities.add(entity);
        }
      }
    }
    for (    Entity entity : affectedEntities) {
      Vector forceDir=GeneralMethods.getDirection(entity.getLocation(),currentLoc.clone().add(0,height,0));
      if (entity instanceof Player) {
        if (Commands.invincible.contains(((Player)entity).getName())) {
          break;
        }
      }
      entity.setVelocity(forceDir.clone().normalize().multiply(0.3));
    }
  }
 else   if (abilityName.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      origin=player.getEyeLocation();
      currentLoc=origin.clone();
    }
    Entity target=GeneralMethods.getTargetedEntity(player,range);
    if (target instanceof Player) {
      if (Commands.invincible.contains(((Player)target).getName())) {
        return;
      }
    }
    if (target != null && target.getLocation().distanceSquared(currentLoc) > 49) {
      destination=target.getLocation();
    }
 else {
      destination=GeneralMethods.getTargetedLocation(player,range,getTransparentMaterial());
    }
    direction=GeneralMethods.getDirection(currentLoc,destination).normalize();
    currentLoc.add(direction.clone().multiply(speed));
    if (player.getWorld() != currentLoc.getWorld()) {
      remove();
      return;
    }
 else     if (!player.isSneaking()) {
      remove();
      return;
    }
 else     if (Math.abs(player.getLocation().distanceSquared(currentLoc)) > range * range) {
      remove();
      return;
    }
 else     if (affectedEntities.size() > 0 && System.currentTimeMillis() - time >= airStreamEntityCarryDuration) {
      remove();
      return;
    }
 else     if (!isTransparent(currentLoc.getBlock())) {
      remove();
      return;
    }
 else     if (currentLoc.getY() - origin.getY() > airStreamMaxEntityHeight) {
      remove();
      return;
    }
 else     if (GeneralMethods.isRegionProtectedFromBuild(this,currentLoc)) {
      remove();
      return;
    }
 else     if (FireAbility.isWithinFireShield(currentLoc)) {
      remove();
      return;
    }
 else     if (isWithinAirShield(currentLoc)) {
      remove();
      return;
    }
 else     if (!isTransparent(currentLoc.getBlock())) {
      currentLoc.subtract(direction.clone().multiply(speed));
    }
    for (int i=0; i < 10; i++) {
      BukkitRunnable br=new BukkitRunnable(){
        final Location loc=currentLoc.clone();
        final Vector dir=direction.clone();
        @Override public void run(){
          for (int angle=-180; angle <= 180; angle+=45) {
            Vector orthog=GeneralMethods.getOrthogonalVector(dir.clone(),angle,0.5);
            playAirbendingParticles(loc.clone().add(orthog),1,0F,0F,0F);
          }
        }
      }
;
      br.runTaskLater(ProjectKorra.plugin,i * 2);
      tasks.add(br);
    }
    for (    Entity entity : GeneralMethods.getEntitiesAroundPoint(currentLoc,2.8)) {
      if (affectedEntities.size() == 0) {
        time=System.currentTimeMillis();
      }
      if (!entity.equals(player) && !affectedEntities.contains(entity)) {
        affectedEntities.add(entity);
        if (entity instanceof Player) {
          flights.add(new Flight((Player)entity,player));
        }
      }
    }
    for (    Entity entity : affectedEntities) {
      Vector force=GeneralMethods.getDirection(entity.getLocation(),currentLoc);
      entity.setVelocity(force.clone().normalize().multiply(speed));
      entity.setFallDistance(0F);
    }
  }
 else   if (abilityName.equalsIgnoreCase("String_Node_Str")) {
    if (origin == null) {
      direction=player.getEyeLocation().getDirection().normalize();
      origin=player.getLocation().add(direction.clone().multiply(10));
    }
    if (progressCounter < 8) {
      return;
    }
    if (destination == null) {
      destination=player.getLocation().add(player.getEyeLocation().getDirection().normalize().multiply(10));
      Vector origToDest=GeneralMethods.getDirection(origin,destination);
      for (double i=0; i < 30; i++) {
        Vector vec=GeneralMethods.getDirection(player.getLocation(),origin.clone().add(origToDest.clone().multiply(i / 30)));
        FireComboStream fs=new FireComboStream(null,vec,player.getLocation(),range,speed,"String_Node_Str");
        fs.setDensity(1);
        fs.setSpread(0F);
        fs.setUseNewParticles(true);
        fs.setParticleEffect(getAirbendingParticles());
        fs.setCollides(false);
        fs.runTaskTimer(ProjectKorra.plugin,(long)(i / 2.5),1L);
        tasks.add(fs);
      }
    }
    manageAirVectors();
  }
}

Fixed version (ground truth):
@Override public void progress(){
  progressCounter++;
  if (player.isDead() || !player.isOnline()) {
    remove();
    return;
  }
 else   if (currentLoc != null && GeneralMethods.isRegionProtectedFromBuild(this,currentLoc)) {
    remove();
    return;
  }
  if (abilityName.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      state=AbilityState.TWISTER_MOVING;
      direction=player.getEyeLocation().getDirection().clone().normalize();
      direction.setY(0);
      origin=player.getLocation().add(direction.clone().multiply(2));
      destination=player.getLocation().add(direction.clone().multiply(range));
      currentLoc=origin.clone();
    }
    if (origin.distanceSquared(currentLoc) < origin.distanceSquared(destination) && state == AbilityState.TWISTER_MOVING) {
      currentLoc.add(direction.clone().multiply(speed));
    }
 else     if (state == AbilityState.TWISTER_MOVING) {
      state=AbilityState.TWISTER_STATIONARY;
      time=System.currentTimeMillis();
    }
 else     if (System.currentTimeMillis() - time >= twisterRemoveDelay) {
      remove();
      return;
    }
 else     if (GeneralMethods.isRegionProtectedFromBuild(this,currentLoc)) {
      remove();
      return;
    }
    Block topBlock=GeneralMethods.getTopBlock(currentLoc,3,-3);
    if (topBlock == null) {
      remove();
      return;
    }
    currentLoc.setY(topBlock.getLocation().getY());
    double height=twisterHeight;
    double radius=twisterRadius;
    for (double y=0; y < height; y+=twisterHeightParticles) {
      double animRadius=((radius / height) * y);
      for (double i=-180; i <= 180; i+=twisterDegreeParticles) {
        Vector animDir=GeneralMethods.rotateXZ(new Vector(1,0,1),i);
        Location animLoc=currentLoc.clone().add(animDir.multiply(animRadius));
        animLoc.add(0,y,0);
        playAirbendingParticles(animLoc,1,0,0,0);
      }
    }
    playAirbendingSound(currentLoc);
    for (int i=0; i < height; i+=3) {
      for (      Entity entity : GeneralMethods.getEntitiesAroundPoint(currentLoc.clone().add(0,i,0),radius * 0.75)) {
        if (!affectedEntities.contains(entity) && !entity.equals(player)) {
          affectedEntities.add(entity);
        }
      }
    }
    for (    Entity entity : affectedEntities) {
      Vector forceDir=GeneralMethods.getDirection(entity.getLocation(),currentLoc.clone().add(0,height,0));
      if (entity instanceof Player) {
        if (Commands.invincible.contains(((Player)entity).getName())) {
          break;
        }
      }
      entity.setVelocity(forceDir.clone().normalize().multiply(0.3));
    }
  }
 else   if (abilityName.equalsIgnoreCase("String_Node_Str")) {
    if (destination == null) {
      origin=player.getEyeLocation();
      currentLoc=origin.clone();
    }
    Entity target=GeneralMethods.getTargetedEntity(player,range);
    if (target instanceof Player) {
      if (Commands.invincible.contains(((Player)target).getName())) {
        return;
      }
    }
    if (target != null && target.getLocation().distanceSquared(currentLoc) > 49) {
      destination=target.getLocation();
    }
 else {
      destination=GeneralMethods.getTargetedLocation(player,range,getTransparentMaterial());
    }
    direction=GeneralMethods.getDirection(currentLoc,destination).normalize();
    currentLoc.add(direction.clone().multiply(speed));
    if (player.getWorld() != currentLoc.getWorld()) {
      remove();
      return;
    }
 else     if (!player.isSneaking()) {
      remove();
      return;
    }
 else     if (player.getWorld().equals(currentLoc.getWorld()) && Math.abs(player.getLocation().distanceSquared(currentLoc)) > range * range) {
      remove();
      return;
    }
 else     if (affectedEntities.size() > 0 && System.currentTimeMillis() - time >= airStreamEntityCarryDuration) {
      remove();
      return;
    }
 else     if (!isTransparent(currentLoc.getBlock())) {
      remove();
      return;
    }
 else     if (currentLoc.getY() - origin.getY() > airStreamMaxEntityHeight) {
      remove();
      return;
    }
 else     if (GeneralMethods.isRegionProtectedFromBuild(this,currentLoc)) {
      remove();
      return;
    }
 else     if (FireAbility.isWithinFireShield(currentLoc)) {
      remove();
      return;
    }
 else     if (isWithinAirShield(currentLoc)) {
      remove();
      return;
    }
 else     if (!isTransparent(currentLoc.getBlock())) {
      currentLoc.subtract(direction.clone().multiply(speed));
    }
    for (int i=0; i < 10; i++) {
      BukkitRunnable br=new BukkitRunnable(){
        final Location loc=currentLoc.clone();
        final Vector dir=direction.clone();
        @Override public void run(){
          for (int angle=-180; angle <= 180; angle+=45) {
            Vector orthog=GeneralMethods.getOrthogonalVector(dir.clone(),angle,0.5);
            playAirbendingParticles(loc.clone().add(orthog),1,0F,0F,0F);
          }
        }
      }
;
      br.runTaskLater(ProjectKorra.plugin,i * 2);
      tasks.add(br);
    }
    for (    Entity entity : GeneralMethods.getEntitiesAroundPoint(currentLoc,2.8)) {
      if (affectedEntities.size() == 0) {
        time=System.currentTimeMillis();
      }
      if (!entity.equals(player) && !affectedEntities.contains(entity)) {
        affectedEntities.add(entity);
        if (entity instanceof Player) {
          flights.add(new Flight((Player)entity,player));
        }
      }
    }
    for (    Entity entity : affectedEntities) {
      Vector force=GeneralMethods.getDirection(entity.getLocation(),currentLoc);
      entity.setVelocity(force.clone().normalize().multiply(speed));
      entity.setFallDistance(0F);
    }
  }
 else   if (abilityName.equalsIgnoreCase("String_Node_Str")) {
    if (origin == null) {
      direction=player.getEyeLocation().getDirection().normalize();
      origin=player.getLocation().add(direction.clone().multiply(10));
    }
    if (progressCounter < 8) {
      return;
    }
    if (destination == null) {
      destination=player.getLocation().add(player.getEyeLocation().getDirection().normalize().multiply(10));
      Vector origToDest=GeneralMethods.getDirection(origin,destination);
      for (double i=0; i < 30; i++) {
        Vector vec=GeneralMethods.getDirection(player.getLocation(),origin.clone().add(origToDest.clone().multiply(i / 30)));
        FireComboStream fs=new FireComboStream(null,vec,player.getLocation(),range,speed,"String_Node_Str");
        fs.setDensity(1);
        fs.setSpread(0F);
        fs.setUseNewParticles(true);
        fs.setParticleEffect(getAirbendingParticles());
        fs.setCollides(false);
        fs.runTaskTimer(ProjectKorra.plugin,(long)(i / 2.5),1L);
        tasks.add(fs);
      }
    }
    manageAirVectors();
  }
}