When does it make sense to transmigrate/reincarnate story characters?
I'm still fairly early on in Disgaea. I've just started Map 4, and Laharl is only level 18 or so.
I see that I have the option to Transmigrate him. As I understand it, transmigration makes a lot of sense for my newly-created characters, as I effectively upgrade what class they are (like Cleric to Priest or Bishop). However, for characters like Laharl and Etna, they can't upgrade their class or change class, so the only benefit seems to be that they may get some more ability points, depending on how much mana I spend.
I'm left with some questions about when it's worth it do this. Are the ability bonuses cumulative, such that if I transmigrate him 10 times, I'll get 10 times worth of stat bonsues? Or will my 2nd transmigration wipe out the ability bonuses of the first?
If they do stack, does it ever make sense to transmigrate as a Genius, since it costs a heck of a lot more mana (8000) to get 10 points, whereas I could transmigrate 10 times for +1 ability points (only costs 10 mana each time!)?
If it doesn't stack, will I ever need to transmigrate again once I've transmigrated at the Genius level?
What's the "Inheritance Bonus" percentage, and how does this affect things?
Story Characters are great to migrate the first 5 times because you get a 5% aptitude bonus for all stats the first 5 times; aptitude % means you gain that much of your equipment's stats as a %. So after 5 transmigrations you get 25% more out of all equipment for that character!
However, transmigrating shouldn't be done lightly unless you can very easily level your characters. You'll have to level your characters over again and gain enough mana for them to transmigrate again.
The main reason for transmigrating to Genius is because of the Inheritance Rate. Inheritance rate is how much of your Skill and Weapon experience you lose when you transmigrate. If you have 1000 Ax Skill and transmigrate with 50% inheritance rate, you now have 500 Ax Skill. Since there is no easy way to grind Weapon Level or Skill Level, losing skill level really hurts. Doing it early on can be good if you're sure you can get the mana/levels back in reasonable time.
If you can't easily get enough mana to migrate your character as a Genius, don't transmigrate yet. Disgaea is not about grinding, it's about grinding intelligently. You're too early in the game to worry about this from what I can tell.
Ability points don't stack in the way you describe; you always get 10 for genius, and you get a set amount of points extra for that character based on their total level.