@General Banane can you share your sav file? also i have no idea what program you used to edit other than save edit online.
@istoleyourname sorry for the late response for some reason i didn't get a notification and saw your post by pure luck.
I use this website you mentioned and upload my save file there to the the clear text like in you picture https://www.saveeditonline.com/
It's a a challenge to do what you want but for example you can change the type of card:
Search for "main_card_id_X": 251.0
The 'X' is random number given by the game and a intern ID, but i can change so be careful
The 251 is the Pokemon Celebi it's the exact same number as in the pokedex entry so go to the official pokemon site.
You can change the 251 to another Pokemon you want like 6 for Charizard
Change the value to "main_card_id_X": 6.0
Then click on 'download save data' at the end of the screen and replace the save file.
If you want my save file then join their discord and pm me and i will send it to you.
The Excel sheet was made by me ^^
Hope it helps