Oh, and by the way, more notes on powerleveling…
The enemies in 5-2 (Lost Dignity) are good to get you to levels in the 60s easily, but you shouldn't go that far if you don't want to. Don't spend hours and hours there, it isn't worth it. 9-4 (Concrete Knowledge), however, is a golden level 99 map. Let me explain:
Due to a quirk in Disgaea's leveling formula (not a glitch, they have it that way on purpose), enemies at level 99 give as much exp as a level 300 enemy. There's basically no difference in experience from enemies in that range. So, the best thing to do when you leveling up characters under level 300 is to find a map with a bunch of level 99 enemies and an experience boost. Map 9-4 is that map, after you pass one Stronger Enemies Bill (normally its monsters are around level 80-85).
What's even better is that it's really, really easy to one-shot the enemies on 9-4. You just need a strong Desco. Desco's most powerful attack (Yog Sothoth) hits a 2x3 block in a straight line in front of her, but when she fuses with another monster into Giant Desco the attack hits with a 3x5 radius. The monsters in 9-4 are arranged just like that, 10 monsters in a 3x5. So, play 9-4 like this: put the EXP and Mana blocks in the geo-panel, have Desco fuse into Giant Desco with another monster you want to level, and then Yog the **** out of those monsters. Boom. Icing on the cake: Desco and the other monster won't share the EXP or mana, they'll both gain the full amount.
Basically, once you beat 9-4 once, pass an SEB and then grind on the level 99 units in 9-4 until the cows come home. Or, more accurately, until you have some units at level 280-300.