The return of the Weapon Mastery System. As mentioned on the main YMMV page, some fans were glad to see it go when Disgaea 3 came out while others weren't as enthusiastic. While being able to tweak the Weapon Mastery rate with the Cheat Shop and some other changes help alleviate some of the backlash, the base is still divided on which of the two methods of gaining skills was better.
The Monster Mounting replacing Magichange. Those who prefer Monster Mounting like that it allows monsters to ferry the humanoid characters, act as a mobile meat shield for weaker characters early in the game, and is not limited by a turn limit. Those who prefer Magichange don't like that humanoids are limited to magic skills while mounting, that the overall uniqueness and stat boosts from Magichange outweigh the turn limit, and that while mounting looks perfectly fine for larger monsters like dragons, it ends up looking silly on the more humanoid looking monster-types like Raspberyl and Metallica.
The plot itself. While many were pleased to see the main trio return to their pre-Flanderization characterizations from the first game and enjoyed the newly introduced cast members, just as many found the Long Lost Sibling angle to be cliched, were put off by Sicily permanently joining the trio, or simply missed the Defenders of Earth.
Character Rerailment: The main cast has been hit hard by Flanderization in their guest appearances over the years since the first game, which at first glance seems to have stuck as of the beginning of this game. In truth, it's more a case of Vitriolic Best Buds than anything, and the character development did stick (and in fact gets expounded on), it's just not obvious from their day-to-day interactions.
Demonic Spiders: Anything that can inflict Poison in your characters, mostly because they are always accompanied with Mothmen on the map. By simply being present on the map, the Mothmen cause the Poison skills to hit much more often, last considerably longer and deal MUCH more damage per turn. In fact, if not cured, being poisoned while a Mothman is around will kill your character in three turns even at full health, even if you have hundreds of millions of hit points.
Designated Evil: The spreading of the Yuie flowers for most of the game. Everyone tries to stop it because it will turn the Netherworld into another Celestia, even though the worst thing that they do is cause minor changes to demons which are only temporary. It's not until it turns out that Xenolith is having angels drained of their life, essentially killing them to do it that it's revealed to actually be bad thing.
Episode 7. Always outnumbered, flooded with Reapers that hit hard and eat your SP, and crippling geo symbols everywhere.
Then you go to the X Dimension of Episode 7. Ouch. To make matters worse, you need to capture one of the Reapers to obtain a part needed for the Land of Carnage.
One could make the argument that Episode 8 is even worse. Same problems as Ep. 7, outnumbered, crippling geo symbols, but also Geo Puzzles and enemies with long ranges. And at the end, you have to fight the boss once, and then a giant version of her a second time without the opportunity to heal up in between.
Ensemble Dark Horse: Laharl's female form became an immediate hit with fans as soon as it was revealed. Likely intentional, as the other characters comment on how they like him much more as a girl, and it's much, much easier to turn him from a boy into a girl in the Dark Assembly than vice-versa.
Fridge Logic: According to the artbook, Sicily is 937; nearly 400 years younger than Laharl. This would mean that, barring an explanation of humans living longer in the Netherworld, Laharl's mother was alive for 400 years before her Heroic Sacrifice to save Laharl.
Fridge Horror: The Overlord Sicily and Pure Flonne the Awakened Angel are too light and comedic to be considered Bad Endings until you consider that there was nobody to rescue the Angels kidnapped by Xenolith.
Hilarious in Hindsight: Sicily is a mysterious young girl who claims to be Laharl's little sister and plans on becoming the Overlord. Why does that sound so familiar?Luckily, unlike Maharl, she does turn out to be Laharl's real sister.
Magnificent Bastard: Xenolith is a soft-spoken, enigmatic figure who turns out to be Etna's older brother. Knowing Etna's innate magical power would lead to her demise, Xenolith claimed the magic-absorbing Artifact of Absolute Death to save his little sister's life, only to realize he had no way of turning it off, causing it to siphon the Netherworld's magic and tear it apart. To fix this, Xenolith began kidnapping angels to drain them of their magic and stabilize the Netherworld, staying under the radar and even deflecting suspicion by defending an angel he would capture later. Once cornered, Xenolith keeps calm and tries to dissuade the party from destroying the Artifact, knowing it would kill Etna if they did, and accepts his defeat with grace when they manage to shatter it without casualty.
Memetic Mutation: Laharl is wearing pants! explanation Laharl's shorts have become such an iconic part of his character design (alongside his antenna hair and scarf) that when his new character design showed that he traded them for pants, many fans became far more fixated on his new pants than on anything else.
Recycled Script: Axel's cameo is almost the same as Asagi's (Both tried to audition by hijacking Lanzarote's concert, but they're too late and missed the concert) The notable differences was that Axel's auditioning for Dark Hero and that the Deja Vu wasn't lost on Laharl's party.
The events of Chapter 2, how Laharl meets and befriends Sicily is eerily similar to how Laharl meets and befriends Flonne in Chapter 2 of Hour of Darkness, down to her summoning Zombies and Dragons to fight the protagonists.
Self-Imposed Challenge: The Cheat Shop facilitates these by having options available from the beginning of the game to gain no EXP, weapon mastery, or skill EXP, or crank up the enemy levels. There is also an option to disallow the player from cancelling assigned commands, which disables some common tricks Disgaea veterans may use.
That One Achievement: Special Voyeur requires that you see every single special attack animation. This normally would have been easy, if a little time consuming, were it not for the fact that it includes the 3 unique skills of Xenolith's first phase and Darkdeath Evilman. You will only ever fight either boss once per cycle, meaning that if they go down before you get to see their skills, you have to start a new cycle just to see them. It can still be a pain in the ass trying to view them even if you're trying to, as there's no guarantee that they'll use all three in one fight, though that's mitigated by the fact that getting a Game Over in this game will simply send you back to the castle. For some advice... The best way to deal with the former is to steal his weapon, choking the amount of skills he has at his disposal in the first place, while the main problem with the latter is that he has one skill that he can't be baited into using, since he will always prioritize using a different one with more power and a bigger strike zone, meaning the only way to force him to use it is to have him run out of SP since it happens to be cost less than the alternative, which in turn means you're either going to need a Spirit that's strong enough to damage him and drain it (and not drain him to 0 or else you have a different problem) or have a unit strong enough to face-tank him until he runs out on his own (though a Lollipop Candy, with its passive HP recovery, can make this easier), which while not requiring anything specific, is doomed to take a while.
That One Boss: So, thought Baal in Disgaea 4 was too easy? Apparently, so did Nippon Ichi, because they took that and made him even harder. He can only be fought in Raesetsu Mode, so his stats are going to be stupidly high (five-hundred million at the very least), his items can't be stolen, he never loses his stationary bonus so he will hit harder the longer the fight drags outnote normally, stationary bonus adds extra power each time a unit attacks without moving, but the Super Time Engine Baal has equipped negates that penalty, has Ultimate Force from Disgaea 4 (the evility in which one of his swords drops on your character the moment it's summoned from the base panel), and a variation of Pringer X's Super Skill Solved evility (specials from a single character cannot be used more than once). Bring him down, and it turns out he has a new form and with it a new evility and will do this five more times. New evilities include inflicting all status effects, increased evasion, summoning mini-Baals, automatic damage at the end of turn, and base panel destruction. Good luck.
The second battle against Xenolith is nigh universally agreed upon to be the hardest non-Superboss in the entire series. He's the weakest main story final boss base stat wise, but his evility more than makes up for it. It siphons 3% of the base stats of any character within 10 spaces of him, gaining up to 30% of their base stats. That's right: he renders grinding, a simple and powerful strategy, completely and utterly useless. A proper plan and intelligent team composition are actually required for once, which can throw off anybody who just powers their way through the games.
That One Level: The battle against Barbara on Chapter 8. You have 5 turns to kill Barbara, three Baciels and four Sea Angels in a stage almost entirely covered by Recovery 20% (everyone recovers 20% of their max HP at the end of each turn), Defense + 50% (halved damage), Ally Lonely (if one of your characters is standing at a red panel, none of your other characters may step in any other red panel in the map) and No Lifting. This is the point where players raising a unbalanced party will have to stop everything and grind one character to be a One-Man Army or grind a balanced party by replacing and creating new, better planned characters.
