There is a trophy for each character in FF Dissidia NT where you have to get A++ ranking three times. A++ rankings are almost impossible to get and will get harder as time goes on and teammates and opponents get better. There are a lot of different solutions that could fix this problem, but a suggestion would be to change the requirement to getting 1st place three times with each character instead. This is much more doable and would be more fun while still incentivising ranked play.