Well, I'd kind of need a bit more information in order to give you the best possible solution here.
Like, are you going to be simply modifying the basic state ranks based on their stats?
Or will you be determining them outright based on their states?
Or will you simply be changing the state ranks from time to time based on certain skills being used?
Either way, a good place to start might be to copy the state ranks out of the data_system and into the associated actors. You'd need to add a line like:
@state_ranks = $data_classes[@class_id].state_ranks
to the initialize method of Game_Actor.
Then change def state_ranks from:
def state_ranks
return $data_classes[@class_id].state_ranks
end
to:
def state_ranks
return @state_ranks
end
Then you could modify @state_ranks however you want. If you ever wanted to reset it to default, just reuse:
@state_ranks = $data_classes[@class_id].state_ranks
Anything more specific than that, though, and I'd need to have a better understanding of what you want to accomplish.
((Also, you may want to make sure $data_classes[@class_id].state_ranks isn't directly refrenced elsewhere in Game_Actor or Game_Battler.))