I was hoping to get help with making gestalt characters for my players to fight in the end game. They're supposed to be incredibly difficult to fight because they're a bonus fight, but the players would get three wishes after defeating all three of them so they're worth the effort. The way they fight is meant to compliment them, but for the sake of discerning one from another:
Heartbank: The healer of the group. I had hoped she has Fast Healing as well as a way to heal her allies. Although she can heal very well, her disadvantage is she doesn't really fight. All she has for protection is her armor and a spiked metal shield. She has an aura that, if players fail to save against, keeps them from attacking her.
Soulbank: The tank of the group. I had hoped she fights unarmed and is capable of taking massive amounts of damage, even getting stronger as she gets more hurt. She should be able to either draw attention from her allies or block off enemies from getting past her. I plan to give her a couple levels of oracle so she can life link with her allies- she draws damage to herself and Heartbank heals it off her. She has an aura that, if players fail to save against, cause them to be shaken until they successfully pass a will save. Her advantage is being able to take tremendous amount of punishment (possibly even staying conscious in negative HP?) but her disadvantage is no ranged combat- she's up close and personal.
Mindbank: The damage dealer of the group. She uses her spells almost primarily for offense. This one is by far the most simplistic one with her advantage being a long-range spell caster but the disadvantage being she uses vocal components for all of her spells- she has to call out the name of the spell to cast them, meaning players will know what the spell is. She has an aura that, when the player fails to save against, causes a -4 penalty to attack, damage, and CMB as long as she's the target.
I should mention their auras only work if the players are looking at them directly. I know it seems odd I give them disadvantages, but I had hoped they would work together to make up for downsides. Heartbank is dangerous because she can heal faster than enemies can harm, Soulbank is dangerous because she can draw damage to herself and block enemies from getting past her (hopefully), and Mindbank is capable of dishing massive damage out. I want to follow the rules for my gestalt characters so in the case of these characters:
Stat array of 18, 16, 14, 14, 12, 10.
These characters are all level 20
They are only allowed one caster class in their career. So for example, if you gained spells or extracts (since they count as spells) from one class, you cannot take another class that has spells. Classes that have spells but archetypes that remove them are acceptable however.
Only one prestige class at a time, but there's no limit on how many prestige classes they can take except for the above caster limit.
I have ideas on how to build these characters but I was wondering if I could ask you all for assistance for these characters. With this information, how would you build any of these characters so that they're scary good at their jobs?