PlayerSync

public class StatSyncMessage implements IMessage {

    private NBTTagCompound tag;
    public StatSyncMessage(){}
    public StatSyncMessage(NBTTagCompound tag) {this.tag = tag;}

    @Override public void fromBytes(ByteBuf buf) {tag = ByteBufUtils.readTag(buf);}
    @Override public void toBytes(ByteBuf buf) {ByteBufUtils.writeTag(buf, tag);}

    public static class StatMessageHandler implements IMessageHandler<StatSyncMessage,IMessage> {

        @Override
        public IMessage onMessage(StatSyncMessage message, MessageContext ctx) {
            final NBTTagCompound tag = message.tag;
            Minecraft.getMinecraft().addScheduledTask(new Callable<Object>() {
                @Override
                public Object call() throws Exception {
                    Minecraft mc = Minecraft.getMinecraft();
                    WorldClient world = mc.theWorld;
                    List<EntityPlayer> players = world.playerEntities;

                    for (EntityPlayer player : players) {
                        if (tag.getString("name").equals(player.getName())) {

                            IFurredPlayer furred = player.getCapability(FurryX.FURRED_PLAYER_CAPABILITY, null);
                            furred.deserializeNBT(tag);
                            furred.setPlayer(player);

                            player.refreshDisplayName();
                            break;
                        }
                    }
                    return null;
                }
            });
            return null;
        }
    }
}

public class EventHandler {
    @SubscribeEvent
    public void playerLoggedOn(net.minecraftforge.fml.common.gameevent.PlayerEvent.PlayerLoggedInEvent event) {
        EntityPlayer playerA = event.player;
        World world = playerA.worldObj;

        if (!world.isRemote){
            IFurredPlayer furred = playerA.getCapability(FURRED_PLAYER_CAPABILITY, null);

            FXPackerHandler.INSTANCE.sendToAll(new StatSyncMessage(furred.serializeNBT()));

            List<EntityPlayer> players = world.playerEntities;
            for (EntityPlayer playerB : players) {
                IFurredPlayer furredB = playerB.getCapability(FURRED_PLAYER_CAPABILITY, null);

                if (playerA instanceof EntityPlayerMP)
                    FXPackerHandler.INSTANCE.sendTo(new StatSyncMessage(furredB.serializeNBT()), (EntityPlayerMP) playerA);
            }
        }

    }
}