Mao gets one for what is probably the most awesome defeat of a final boss ever: Kill him? Nah! Why kill him when you can make him your own personal lab rat for all of your gruesome experiments?
This is taken a step further when you realize what said final boss' motives are. Throughout all of Disgaea 3, Super Hero Aurum had been posing as Geoffrey, Mao's butler, and raising him to be the ideal Overlord, as he perceived it, all so he could become a hero again - either living as one by killing Mao or dying as one by losing to him in battle. For Aurum, obscurity was worse than death; by the time the battle was concluded in the good ending, Mao came to the decision that his father's murderer didn't deserve death.Say it with me:
Raspberyl Mode adds one: Raspberyl storms heaven itself in order to acquire the "Heart of an Angel" and become the Ultimate Delinquent. Then she forces a meeting with the Archangel, who turns out to be a promoted Flonne (an awesome moment itself considering how recently she was a mere Angel Trainee). Flonne demands to know why Beryl really did this, and Raspberyl grudgingly admits that really she's doing it all for Mao: their rivalry has always been what has driven him to greatness, by making him desire to one-up Beryl by becoming the Ultimate Honor Student. Everything Raspberyl has done, all the hard work and volunteering, was to inspire her friend. Flonne tells her she doesn't need the Heart of an Angel, she already has one.