protected function gNightfall()
{
$nightfall = $this->getNonMutatedProperty('nightfall');
if ($nightfall == null) {
return null;
}
$definition = manifest()->activity($nightfall['specificActivityHash']);
$skulls = manifest()->activity($nightfall['activityBundleHash']);
$activity = new Advisors\Activity($this, $definition, $this->nightfallResetDate);
$activity->addLevelRewards($skulls);
$activity->addActiveSkulls($skulls, $nightfall['tiers'][0]['skullIndexes']);
return $activity;
}