NPC Solution?

How do I make it work, by hitting the PC since my code does not work..

PHP:

public function onDamage(EntityDamageEvent $e){
    $o = $e->getEntity();
    if($e instanceof EntityDamageByEntityEvent){
      $d = $e->getDamager();
      if($d instanceof Player && $o instanceof NPCFfa){
          $e->setCancelled();
          $player = $d;
          $sender = $d;
      $this->getServer()->loadLevel("ffa");
          $count = count($this->getServer()->getLevelByName("ffa")->getPlayers());
           if($o->getNameTag() === "§bFree for All\n§eTouch to play!"){
     $this->getServer()->loadLevel("ffa");
     $player->teleport($this->getServer()->getLevelByName("ffa")->getSpawnLocation());
            $player->sendMessage("§cTe has unido a FFA\n§b".$player->getName()."§c Te deseamos suerte!");
            $player->setFood(20);
    $player->setHealth(20);
    $player->addTitle("§3§lFFA§r", "§7» §f¡Enjoy your stay! §7«");
    $player->getInventory()->clearAll();
    $casco = Item::get(Item::DIAMOND_HELMET, 0, 1);
$casco->setCustomName("§bCasco De Diamante");
$player->getArmorInventory()->setHelmet($casco);
$peto = Item::get(Item::DIAMOND_CHESTPLATE, 0, 1);
$peto->setCustomName("§bPechera De Diamante");
$player->getArmorInventory()->setChestplate($peto);
$pantalon = Item::get(Item::DIAMOND_LEGGINGS, 0, 1);
$pantalon->setCustomName("§bPantalones De Diamante");
$player->getArmorInventory()->setLeggings($pantalon);
$botas = Item::get(Item::DIAMOND_BOOTS, 0, 1);
$botas->setCustomName("§bBotas De Diamante");
$player->getArmorInventory()->setBoots($botas);
$player->getInventory()->addItem(Item::get(276,0,1));
$manzana = Item::get(Item::GOLDEN_APPLE);
$manzana->setDamage(20);
$manzana->setCount(6);
$manzana->setCustomName("§6Golden Head");
$player->getInventory()->addItem($manzana);
           }}}}