Meowing Mewtwo

You're...funny sometimes. xD
No offence. :\

Anyway, yeah, I wasn't even aware of the new PMD game.

I searched the Groudon image through Unlz-GBA and replaced the image. I think there are numerous tutorials on editing the title screen though. I ain't much of a graphics expert myself, so I can't really help you much on that department.

Anyway, you don't have to worry about leaving messages in VM's.
And don't worry. I'm sure, once you will share your hack here, you'll start getting a couple of VM's.

Try this one, but if still does not work, then I have no idea why it is not working.

You're adding a PKMN which doesn't exist in the third generation games, right?
If you are, then there is a way to add some without replacing the existing ones, I think...
There are 20+ blank slots after Celebi and before Treecko. Those blank spots can be used, however, their cries, by default, are Unown.

But there is another way to add a new PKMN without replacing any other which are currently existing, but I have no slight idea how to do that.
But I know the guy who has accomplished that though, so you are probably better to ask him instead of me. =/
This is his thread, by the way. He already locked and discontinued the project, 'cause he switched into FireRed.

thanks~