Alec
Defeat Salome and Alec in Chapter 8-6.
Asagi
Reach level 1,000 and get 100,000 mana. Select the "Challenge the next protagonist" option in Zeta's wish system, then defeat Asagi.
Castille
Reach level 100 and get 5,000 mana. Select the "Fight with hero" option in Zeta's wish system, then defeat Castille.
Dark King
Reach level 120 and get 5,500 mana. Select the "Defeat Dark King" option in Zeta's wish system during Chapter 6 in your third cleared game and defeat Dark King.
Flonne
Reach level 70 and get 3,000 mana. Select the "Fight ally of justice" option in Zeta's wish system, then defeat Flonne, Etna, Laharl.
Pram
Kill over 60 allies before Chapter 9 and defeat Pram.
Prinny
Reach level 10 and get 1,000 mana. Select the "Make a Prinny" option in Zeta's wish system, then kill a Prinny in a normal battle.
Salome
Reach level 180 and get 8,000 mana. Select the "Fight with Salome" option in Zeta's wish system during Chapter 5, then defeat Salome.
Zeta
Reach level 300 and get 15,000 mana. Select the "Fight with the strongest demon in space" option in Zeta's wish system, then defeat Zeta.
Easy Mana
Getting Mana this way involves healing and may cost some HL. First, select the character you want to earn Mana for and make them the leader. Then, summon all of your characters and any weapon (preferably a sword). Have the leader throttle all of the summoned characters until they are completely obliterated. Check your status to see how far up your Mana has increased. Repeat this as many times as desired. Note: Do not bother thrashing lower level characters; the higher the level, the more Mana you get for killing them.