The 30d6 is if an evil opponent gets attacked with it more than once in a day.
A tarrasque has an Int score of 2. Can't take class levels. If you mean attacking the Tarrasque, then melee needs it.Bralani's Sprint Makes CHOMPY a happy Taurrasque
So is any "Skill in place of AC" maneouver. But then again, Diplomancer builds would get the most mileage out of it. But that is only a TO build.deva's Diplomatic Defense is completely OP at higher levels.
I have forgotten to add some Preqs to the manoeuvers though. I'll add them in now.