.java

preinit:
snw.registerMessage(MessageSyncManaRegen.RegenManaSyncHandler.class, MessageSyncManaRegen.class, 9, Side.CLIENT);

Sync mana regen packet:
public class MessageSyncManaRegen implements IMessage
{
	int id, w, u, b, g, r;

	public MessageSyncManaRegen(){}

	public MessageSyncManaRegen(int id, int w, int u, int b, int g, int r)
	{
		this.id = id;
		this.w = w;
		this.u = u;
		this.b = b;
		this.g = g;
		this.r = r;
	}
	
	@Override
	public void fromBytes(ByteBuf buf)
	{
		this.id = buf.readInt();
		this.w = buf.readInt();
		this.u = buf.readInt();
		this.b = buf.readInt();
		this.g = buf.readInt();
		this.r = buf.readInt();
	}
	
	@Override
	public void toBytes(ByteBuf buf)
	{
		buf.writeInt(this.id);
		buf.writeInt(this.w);
		buf.writeInt(this.u);
		buf.writeInt(this.b);
		buf.writeInt(this.g);
		buf.writeInt(this.r);
	}

	public static class RegenManaSyncHandler implements IMessageHandler<MessageSyncManaRegen, IMessage>
	{
		@Override
		public IMessage onMessage(MessageSyncManaRegen message, MessageContext ctx)
		{
			if(Minecraft.getMinecraft().thePlayer.getEntityId() == message.id)
			{
				EntityPlayer player = Minecraft.getMinecraft().thePlayer;
				AAExtendedPlayer props = (AAExtendedPlayer)player.getExtendedProperties(AAExtendedPlayer.EEPName);
				props.addMana(new Mana(ManaType.W, message.w));
				props.addMana(new Mana(ManaType.U, message.u));
				props.addMana(new Mana(ManaType.B, message.b));
				props.addMana(new Mana(ManaType.G, message.g));
				props.addMana(new Mana(ManaType.R, message.r));
			}
			return null;
		}
	}
}

Original mana regen packet:
public class MessageRegenMana implements IMessage
{
	int id;
	public MessageRegenMana(){}

	public MessageRegenMana(int id)
	{
		this.id = id;
	}

	@Override
	public void fromBytes(ByteBuf buf)
	{
		this.id = buf.readInt();
	}

	@Override
	public void toBytes(ByteBuf buf)
	{
		buf.writeInt(this.id);
	}

	public static class RegenManaHandler implements IMessageHandler<MessageRegenMana, IMessage>
	{
		@Override
		public IMessage onMessage(MessageRegenMana message, MessageContext ctx)
		{
			EntityPlayer player = (EntityPlayer)ctx.getServerHandler().playerEntity.worldObj.getEntityByID(message.id);
			AAExtendedPlayer props = (AAExtendedPlayer)player.getExtendedProperties(AAExtendedPlayer.EEPName);
			props.addMana(new Mana(ManaType.W, 1));
			props.addMana(new Mana(ManaType.U, 1));
			props.addMana(new Mana(ManaType.B, 1));
			props.addMana(new Mana(ManaType.G, 1));
			props.addMana(new Mana(ManaType.R, 1));

			ArcaneArtificing.snw.sendToAll(new MessageSyncManaRegen(player.getEntityId(), props.getWhiteMana(), props.getBlueMana(), props.getBlackMana(), props.getGreenMana(), props.getRedMana()));
			return null;
		}
	}
}