Laharl's Overlord Wrath, Flonne's Flonnezilla, Etna's Chaos Impact, Adell's final one.... *name escapes me*, Big Bang from Disgaea 2, Tiger Charge from Disgaea 2, Night Sever, and the set of Tera spells from the original Disgaea, not from Disgaea 2.
For practicality in battle, I'd say Big Bang, Winged Slayer, and Avalance. The relocating range on Avalance is quite nice.
Flonnezilla is level 50 in Disgaea 2 ((assuming level follows the other characters' pattern)) She doesn't get it in the other Disgaea games.
