During the game in both normal and Etna Mode, there are extra stages and worlds in which you can enter by passing its corresponding bill via the Dark Assembly. Completing some of these unique stage groups can gain you extra pary members if playing in the normal mode. However, They cannot be recruited in Etna Mode, but can still be fought. Plenair can be recruited in both normal and Etna mode in the player's current by stating a New Game Plus, then talking to her and choosing the blank option. Do not worry, the Dark Assembly will still be accessible, but a Prinny will stand where Plenair used to. Note that all extra party members will leave when starting a new cycle and must have their stages re-completed in order for them to join you again. (Plenair must also be revisited to re-recruit her.) All recruitable characters will retain any Levels, Abilities, and Equipment upon re-recruitment.
This bill requires 1000 Mana to pass. There are three stages within this area. The final stage contains General Carter, a villain from the main story. During this fight Carter will be assisted by four EDF Soldiers and two Astro Rangers. (Prism Red recolors) This stage is the only stage in which the "Astro Suit" Armor can be seen or stolen. The player receives an ending upon clearing this stage and will be asked to start a new cycle. This stage cannot be played in Etna Mode.
This bill requires 2000 Mana to pass. There are five stages within this area. The Final stage contains Priere, the protagonist of the PS2 game La Pucelle. She is at level 2000 along with two level 1500 enemies as support. (These levels and statistics are doubled if fighting her in Etna Mode while a New Game Plus. If fought in a new Etna Mode Game, stats will be the same as normal, no power increase.) Upon clearing the stage, she will join the player's party for the duration of his/her current cycle if defeated in Normal Mode. If defeated in Etna Mode, there will be an alternate dialouge scene, but she will leave, preventing recruitment. In battle, Priere excels with Attack power abilities, and is considered a Monster-type character.
This bill requires 5000 Mana to pass and contains two stages. The second stage contains Marjoly, the main villain of the PS2 game "Rhapsody: A Musical Adventure." She is at level 4000 and has unique accessories each named after her henchmen. Upon her defeat, she will join the player's party if playing in Normal Mode for the duration of his/her current cycle. In Etna Mode, there will be unique dialouge scenes, but Marjoly will leave, preventing recruitment. In battle, she is a Monster-type character that is the exact opposite of Priere, being strong with Magic spells, armed with the "Tera" level spells of all four elements.
All that is required to unlock this stage is to defeat both Priere and Marjoly in their stages. This stage will appear as soon as you do so. In this stage lies Overlord Baal, the game's strongest enemy. Since Baal is the game's strongest enemy, only powerleveled parties should attempt the fight. In Normal Mode, it's just the player versus him, no catch or special hindurances. If playing in Etna Mode, Baal will be even stronger, and will have some level 1 Prinnies for some very weak assistance as well as Geo Effects powering him up that must be disposed of. Upon defeating him in Normal Mode, you can fight his strongest form by revisiting this stage,where he will be in a Prinny's body and have his stats doubled. Passing all 20 "Stronger Enemy" bills furthers his power. Prinny Baal cannot be fought in Etna Mode. If Baal is defeated along with Priere and Marjoly while playing Etna Mode, the player will receive an alternate ending to Etna Mode, and then will be asked to start a new cycle.
"Cave of Ordeals"
This bill requires 700 Mana to pass and has five stages. This is essentially a training ground. The game's second-best leveling site is within the third stage of this area. "Stronger Enemy" bills make this stage even better for leveling. The fifth stage CANNOT be completed without two Thief characters or Captain Gordon active during the battle, since an enemy is on a seperate inland that only the two aforementioned characters can help traverse. Upon completing the Cave of Ordeals, the player will receive the "God's Hand," the highest tier Fist weapon as well as unlocking the "Demonhall Mirror." This area is also the only place in which the "Arcadia" accessory can be seen or stolen.
Upon completing the Cave of Ordeals while in Normal Mode, a seperate stage will be avaliable to play, each time facing a different enemy. In most of these stages, you will fight legendary people hinted upon throughout the story of the Disgaea universe. (All of them are normal class recolors.) Upon entering for the sixth time, you will fight Adell from Disgaea 2. Beating him will allow him to join your party. Entering again will allow you to fight both him and his friend Rozalin from the same game. Defeating them both will cause the both of them to join the player's party for the duration of the player's current cycle. In battle Adell and Rozalin are both Monster-type characters. Upon entering a final time, the map will become a shade of Cave of Ordeals 3, with nine Galactic Demons and an EXP +100%" Effect, making it the game's second best leveling site (with the first being Etna Mode's Cave Of Ordeal 3 with Max "Stronger Enemies" passed). The Demonhall Mirror cannot be accessed in Etna Mode. Adell and Rozalin are also not recruitable in Etna Mode.
Upon passing all 20 "Stronger Enemy" bills and having Captain Gordon in your party, you can battle Overlord Zetta, the protagonist of the PS2 game "Makai Kingdom: Chronicles of the Sacred Tome," which takes place in another region of the Disgaea universe. To access the actual stage, pass the bills mentioned above, then choose "Primoridal Soup" from the Stage selection menu. You will only enter Zetta's stage if Captain Gordon is in the party. He will be assisted by four Manticores, two Wingman, a Vampire, a Succubus, and two Dragons. He also has various Geo Effects that need disposing of. He joins the player's party at level 3200 (Or 9999 if all Enemy Bills were not undone after unlocking) for the duration of the player's current cycle. (Note that you MUST talk to the Dimensional Guide before undoing the "Stronger Enemy" bills, otherwise, the fight will not be accessible until they are re-passed.) In battle, he is an ATK-based characetr with little to no movement range, but having the games highest Aptitudes (180% in all statistice) as a trade-off. He cannot be fought or recruited in Etna Mode.