Adding effects is a lot of trial and error so far. I don't know If I can put a new effect on an ability, but that's down the road. I did make chubby a 3 x multiplier instead of 2. This is what I'm working with 
Funny enough chubby chocobo was unironically good for me, cause since i have no life i actually got around 9k battles for him, so he was doing okish damage lol.