It's plain wrong, the WHOLE code and it's logic. Still, your for loop doesn't consider party members. You create for loop for party members and you still focus on the player, in short, your actual for loop is useless, has no use.
Here you go the proper code.. Change the msg
if (getNpcId() == _barakielId)
{
for (L2PcInstance newNoble : player.getParty().getPartyMembers())
{
if ((newNoble.isSubClassActive() || player.getLevel() >= 75) && !newNoble.isNoble())
{
newNoble.setNoble(true, true);
newNoble.broadcastPacket(new SocialAction(player.getObjectId(), 15));
newNoble.sendMessage("You have received nobless status by killing Raid Boss Barakiel!");
}
else
newNoble.sendMessage("What a shame. You don't meet the required criteria (subclass is not active or lvl is not greater or equal 75 or you are simply already a noble.)");
}
}