These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Devil Survivor 2
Please note that, as discrete works, the Video Game and Anime adaptations have distinct YMMV tropes and are organized under separate headings below. Kindly add any new entries to their appropriate sections.
Esoteric Happy Ending: The Liberator Ending. You decide to kill Polaris. The only problem is that you've removed all supernatural influence from the world, even the good ones. The void isn't undone, leaving only Tokyo and a sea of undrinkable water. You pretty much doomed what's left of humanity to slowly starve to death, and yet the game treats this ending as a good thing. On the bright side, the disaster is finally bringing out the best in people.
As the pairing is popular in Japan, the anime decides to push what little interaction that the game failed to give Jungo and Airi (since the game states they ARE partners) and make it their main point.
Protagonist/Nitta also became popular following the anime's release.
Foe Yay: Let's just say Ronaldo likes to mention Yamato a bit too much if the letters "J" and "P" are in a sentence. Too bad Yamato knows diddly-squat about him.
Fridge Brilliance: On the first day of the game, you can run into Joe (before he needs your help fighting off demons), and respond with "Long time, no see" when he remarks that you look familiar. This boosts your relationship with him, but it's never explained who he mistook you for. After Polaris has restored the world of the past for a New Game+, it's easy to see this as the two of you holding on to your memories of each other. There are similar dialog choices scattered throughout the game, such as telling Daichi that you and Io already know each other, and they tend to be the right ones.
Game Breaker: Now that racial skills can evolve, previous combinations in the previous game become EVEN more broken than before if you put a good combination.
Evil Flow + Matchless = Attack twice from 6 squares away from the enemy AND heal yourself twice if needed. Or Evil Flow + Chaos Breath for functionally 11 attack range in exchange for barely getting turns. Or Winged Flight + Chaos Breath to counter the movement debuff. Or Blood Treaty + Victory Cry for free Megidolaon attacks.
Multi Strike, a skill that does damage based on both agility and strength, always hit the same amount of time(2-7 depending on the agility difference instead of random like say, Deathbound) and relatively low HP cost. Also, since its an Agility based move, it has priority over most other actions. A skirmish after this skill is usable against non Physical repelling enemy generally consists of use Multi Strike, win, next battle. Toss in Pierce/Pierce + and Drain Hit, and you'll pretty much never need healing ever again.
Holy Dance retains its status from DS1, coming relatively early, has far less cost than Megido, and is more effective than Megidolaon against single targets. Plop it on your best Magic-based demons (preferably with Victory Cry/Mana Aid), and dance the night away.
The Auto Skill Grace + Drain. Grace has your character cast Prayer at the start of every battle, which heals your party to full and cures any status ailments. If you give Drain to someone with a high Magic stat, the MP stolen from enemies will both offset Prayer's high cost AND heal the player if they still need it.
Individual Demon wise there's Da Peng and Lucifer. Da Peng has perfectly placed stats and innate skills for Multi Strike, and best of all, it's not a unique demon and comes with one of the best Racial skill in the game; while Lucifer has all around good stats, and hidden resistance modifier to everything even Almighty and Reflect Curse, which stack with its innate resistance to everything. Their downside are they are realistically only unlockable in New Game+ thanks to their high level, that and you need to take Al Saiduq's route to unlock Lucifer.
There's also Purple Mirror and Titania. Which are demons in the 50s-60s that repel/null almost everything. Put on phys repel and a null curse/repel wind to the two things they are weak to, and you have demons that can only be harmed by almighty.
Hathor is a low-level demon with a crippling weakness to Phys, but is one of the earliest available magical nukers. Have her inherit Magic, give her a few Dances, and watch as she blows through Septentriones with relative ease.
Ho Yay: One could make a serious case for Yamoto having a severe crush on the Hero (albeit due to his stunted emotional understanding he doesn't view it in those terms). To wit, not only does he make it quite clear he regards the Hero as his most reliable subordinate and has many moments where he drops his Jerk Ass manner (as much as he's capable of at least) and acts relatively decent to said Hero. In fact he will flip his shit if you don't pick the Chaos route, even trying to murder the other good guys for "corrupting" the Hero, who he is convinced would join his side again if only the meddling secondary influences were removed. The telling part about this behavior is that he really wouldn't NEED your Hero's help explicitly by this point, he just wants him by his side no matter what. And, if you get him to rejoin you, he phrases the way he felt for you as "yearning".
Lampshaded by Hinako if you tell her Yamato called to tell you he likes you:
Hinako: ...You know, you shouldn't joke like that or people will take it seriously.
At one point he smiles 'teasingly' at you. At another, he says "That's my [character name.]"
There's also a part where Joe thinks Daichi is confessing his love to him. He says that he hasn't done anything like that before... but he thinks Daichi is adorable and is willing to make an effort.
Also a large amount of Les Yay between Airi and Hinako, where Airi starts of snarky (tsun) towards Hinako, and eventually seriously warms up to her beginning with complimenting her dancing.
Dubhe in general has become a complete joke in GameFAQs, to the point that anything that relates to the sentence "i can't beat Dubhe help?" is most likely going to be answered with the word "pirate".
The special operation Io performs to rescue Daichi in Nagoya is slowly becoming popular.
Rescued from the Scrappy Heap: In Devil Survivor, the Dragon race was quite poor, with a nearly useless racial skill and generally having lackluster stats, leading them to be ditched for the superior Vile race. In Devil Survivor 2, the Dragons are far improved, with stronger demons and a Game Breaker racial that allows them to attack from great distances and throw out heals and revives from long range. Combined with the Vile's enhanced racial skill, and you can practically snipe enemies from across the map.
The Scrappy: Many fans think that Daichi is this because he whines a lot more than Yuzu does in the previous game.
Not to mention the person Ronaldo wants to avenge isn't even dead! (At least until he's slain by the demons he summoned). Ronaldo, admittedly, has no way of knowing this, especially since Yamato felt free to claim the kill sight unseen.
Plus the fact that while in Ronaldo's route, Yamato dies after saving the protagonist and co., Ronaldo in Yamato's route dies after a last failed attempt on killing Yamato AFTER Yamato spares his life and offers him a spot in his merit system meaning Yamato kills him by self defense and not out of spite.
Finally, Ronaldo's treatment to Al Saiduq. He tries to kill the latter just because he doesn't agree with the latter's principles. Yamato also wants Al Saiduq dead, but at least he knows Al Saiduq is a Septentrione, so he's legitimately worried what would happen should a Septentrione win.
You can add though that Rolando' is directly responsible for killing off many of the fan favorites listed above intentionally as well as unintentionally.
Keita is generally disliked for being a jerk with no real development or redeeming qualities (unless you go through his FATE route but even then he's still a huge Jerkass in comparison to Yamato who does show change in his character) (Unless you kill off Jungo, a much better liked character.)
And he threatens to kill you if you try to make friends with him. Multiple times.
Tier-Induced Scrappy: Daichi has balanced stats, but balanced is inferior to specialized in this game. In particular, he's a worse Physical attacker than Jungo and Keita, and a worse Multistrike user than Hinako or Keita. Because of this, once Hinako becomes faster and more powerful than Daichi, he's tossed aside.
Io and Makoto to an extent. Because they're Magic Knights that lean toward attack and magic trying to balance it out, one stat will be better than the other but in exchange will leave the vitality and agility at a horrible pace. As a result Yamato is the best choice of the Magic Knight because instead of balancing all of his stats out, he maxs attack and magic while sacrificing vitality and agility making him a Glass Cannon instead of a Magic Knight that favors either attack or magic.
The Woobie: It seems one of the requirements of being a Devil Messenger is being in a lot of pain. Naturally, the job requires being the recipient of even more pain, with the Nicaea System helpfully showing you the gruesome demise of everyone you fail. Since you can't be in five places at once, you will fail without careful planning (or waste all your time socializing). Often. Oh yeah, did I mention if you don't get the very tough aliens dead, they'll kill the world? No pressure, folks!
Alas, Poor Scrappy: Poor Keita's Jerkassery makes them a pain to deal with in the game. Then he's brutally electrocuted Taking the Ziodyne for Hibiki. Also, he's nicer than he was in the game and is a straight up Tsundere.
Angst? What Angst?: JP are largely unfazed by demons attacking earth, or about other people getting killed, because they saw it coming and were concerned only with their larger agenda of preventing the world as a whole from being extinguished.
In ep. 9, after some severe losses and considerable trauma the previous episode, some of the group (namely, Hinako) are cheerful and rather flippant. Of course the events of that episode are just one more hammer blow and by the end of it everyone except Yamato and Fumi is clearly shaken.
Base Breaker: Is it a well written different take on the series? Or just a lazy attempt to make an Evangelion clone?
The ending itself is one. Ether it's justified and needed, or it's out of no where with no build up.
Yamato became one by the last few episodes. He'd seen as ether a very well done Anti-Hero who borderlines Anti-Villain, or he's hit with a horrible cause of Flanderization that makes him more like Gendo Ikari then his in game self and becomes the final boss for little reason.
Faux Symbolism: Lucifer, champion of chaos and freedom is summoned to defeat Satan, agent of Law and Order and has been summoned by Yamato, who plans on brainwashing everyone to make his Meritocracy a reality.
Fridge Logic: There is no given reason or explanation for why Yamato survived Alcor's suicide attack. He was even struggling and couldn't get out of his wire during it.
It might be that the Dragon Stream was activated (indicated by the tower lighting up) seconds before the attack and shielded him from the explosion.
Yamato rushing to Hibiki's rescue after receiving his Death Clip as Alcor revealed. Risking his life in the process to the point even Makoto is scandalized by his sheer recklessness. Not to mention he still treats conversations with Hibiki alone as worthwhile despite his newfound habit of immediately dissing everyone else thanks to his adaptational jerkass upgrade. On the other hand Hibiki too spends more time thinking about Yamato and his motives than the fate of the world, binging most conversations back around to him especially with Alcor.
In episode 10, despite all the insults thrown his way Yamato goes out to fight Lugh but saves Hibiki in the process, keeping in mind that Hibiki could have called Byakko to catch him from his fall and ends up doing so a few minutes later after forcing Yamato to let go of his hand. They spend most of the battle fighting each other rather than a Lugh-possessed Physical God Io. Mind you, they were fighting about whether or not to kill Io. When Lugh attempts to kill Yamato during the squabble, Hibiki ends up pushing Yamato out of the way instead of letting him get killed. At the end of the episode, Yamato prevented Hibiki and Io from falling to their death. He then tells Io that he won't let Hibiki die because in his own words, "Hibiki is mine."
The final episode has Hibiki holding Yamato before he dies and crying for him telling him he doesn't have to shoulder everything anymore. Later on after Hibiki resets the timeline, he sees Yamato and goes up to him. Yamato still remembers Hibiki and while he denies having no friends and smiles acknowledging him in the end before his car drives away.
Tiny Yamato apparently taught Alcor about chess, green tea and conversations and Alcor would like to think they were friends. Even now, they're on friendlier terms than the game.
In the fourth episode, everyone looks super-serious when they try to hold each other up with their highly threatening cell phones. Why exactly they would do that with a summoning device that takes time to work is baffling.
Oddly, the phones could be used as 'guns' in-game, with characters (in cutscenes, anyway) able to zap targets through the summoning app... somehow. Since that ability is absent in the anime, however...
In the fifth episode, Hibiki tries to act cool and aloof by constantly keeping his hood up. His hood with giant floppy bunny ears on it. Again, dead serious.
In the eighth episode and beyond, Hinako's head is covered in huge rough bandages. This makes a ridiculous contrast with her perfect skimpy dancer outfit and how everyone treats the bandages as if they were perfectly normal and not even there. Like mild Fan Disservice that's being paraded as the opposite.