There's a folder called "datafiles" that contains a number of json files. ability_a.json, ability_b.json, etc. Changing the values in those files is how you change the abilities.
char_a.json and char_b.json control the stats for the characters.
I've updated the page for the game with a break down of what each of the values in the different file types do. Does the update description answer your questions?
