Give this a shot:
I tested this on melonDS 0.9.2
In order for it to setup everything properly, you'll need to load into the game and enter a battle at least once. Afterwards, you can activate, or reactivate, everything from
Geo Stuff.
For "Infinite Health", go to
Battle -> Player -> Health.
For "God Mode" go to
Battle -> Player -> State -> Temporary Invincibility.
For "Infinite Zenny" go to
Game Pointers -> General Data -> Zenny.
For "Infinite Star Shards" go to
Game Pointers -> ??? (Other Items) -> Star Frags. Didn't know much about this memory region so I named it how I felt about it.
For "All Weapons" go to
Game Pointers -> Items -> Weapons.
For "All Battle Cards" go to
Game Pointers -> B.Card -> Folders -> Cards -> Card. Now, how this works is you'll type the folder index, then the card index, and then you'll be editing that specific card in your folder (if you don't know, an index starts at 0
not 1). Doesn't just give you cards, although you can kinda cause it to give you one, but I thought this would be sufficient and I created a drop down list for all the cards.
This is all I got and there are more things to be filled out such as key items and what not, but I don't wanna do it.