I like this, but let's adapt it more. When you make a character you can choose Defense, Reiatsu, or Strength bases for you character. How about when they choose one of those their chances of obtaining a specific resurrection.
Example. If someone chooses strength based they have a higher chance of getting Shawlong, Del Toro, Grimmjow, etc. Rei based they get Ulq, Baragan, Hallibel, etc. You get the idea?