cBliss Tool patches the gct to force up to 10 costumes for every character, Mewtwo and Roy included. The tool has a menu to change how many costumes you have per character. If you change all the costume counts to be the original ones in Project M (aka decrease them to fit the standard Project M) except for Mewtwo, you'll have what you're trying to get.

There's a list of characters on the right of the program. Click on each character, click on the small button, and you'll be able to change the number of costumes for everybody. The ones already having 10 costumes in Project M won't be decreased even if the number in the program changes though.

Okay. Can this be done on Mac at all? Or am I gonna have to go windows? If I do it's not an issue. Just annoying to have to switch over to Windows if I don't have to lol

Well, I've setup all my cosmetics and it seems to be working like a charm so far. I'm getting a crash with one of my Sonic slots but I think that it might be exceeding the filesize with project M's Sonic psa (my old setup didn't have any psas so ya).
I'll put up my gct when I have the chance in a bit. Also when adding more csps to your css I'd recommend using indexed pngs to save space. The file size is very easy to exceed, especially with the size of PM's menu stuff and the addition of Roy, I had all my csps indexed at 255 colours before and it was still no good, so I had to turn half of them down to 100 in order to avoid crashes.
So yeah, all seems to work like a charm though. I'll put the file up in a couple hours when I get the chance.

EDIT:

Okay here's the gct: https://www.mediafire.com/?akmhuups63svgwq

It's just Project M 3.0 with their additional costume slots as well as the Dr Mario changes taken out and Mewtwo2000's cBliss with improved stability put in, with 10 slots per character. I'll put up a txt file with the code list on it after, I've got it segmented to show the Project M code I've taken out.

Remember to get Hochin's sc_selcharacter.pac on the previous page and be careful with bringing the file size up on it too high.

EDIT2:

Here's the txt with the codes in a more documented fashion, so you can add more of your own stuff to it if you please: https://www.mediafire.com/?o573wbv3cad6oh2

I had some other bits of the project M code documented that I was interested in modifying but I took that out since it isn't related to cBliss. But I basically have a general idea where the Roy/Mewtwo clone enginey codes are at and where some stage select stuff is at, but I'm probably only going to pursuit modifying the stage select stuff from here on out since I wanna get my expanded SSS working with it.

I'm like completely new to this. Is there anyway to choose what character gets the extra textures? All I'm really trying to do is add some extra slots for Mewtwo. I've got two costumes with the appropriate images as well. Any help is much appreciated.

Every time I try to actually play it won't work cause the game freezes every time I hit Brawl. Can someone help me as to what I should get rid of or add in a certain folder? Note I'm not really good at this hacking stuff so.. yeah lol

Help is appreciated

I just wanted to know how I can get my default CSS back. I didn't put the custom one on so I have no idea how that works.

As far as the Pkmn go for PT, I see him as 27, 28, 29, and 30 in brawl box. Which is squirtle , ivy, char, and pt himself. What number's are they and if I do change the portraits will they all show up on pkmn trainer's original portrait where they go? Ex: Squirtle next to trainer, ivy diagonally above trainer, and charizard directly above him.

Thank you