Digital Devil Saga/YMMV

Complete Monster: Serph Sheffield is a Manipulative Bastard who manipulates everyone and anything around him, including convincing an innocent girl called Sera he honestly cares about her, all in his quest to reach the power of God. He uses Sera's growing love for him to push her Psychic Powers into further maturation, only to express disgust at Seras creation of a virtual paradise consisting of AIs she uses to escape the pain of his experiments. When Colonel Beck proposed to change Seras paradise into a training simulation for creating stronger AIs, Serph overrides Heat O'Brien's warning against destroying Seras mental condition and tells Beck to proceed. After a desperate Heat pulls a gun and demands the project to stop, Serph tells Heat that a human's mind is no different than a machine, and that his subjects, including Sera, were expendable and could be replaced, before manipulating Argilla into killing Heat. After being turned into a demon by a heartbroken Sera, sending a massive data surge into the now black Sun, Serph goes on a killing spree starting with Beck and Argilla before being killed offscreen. Refusing to accept that he is dead, he re-appears at the EGG facility as Solar Data and tries to kill the AI Serph and Heat while proclaiming to have the power of God. A cruel and manipulative young man, his actions are largely responsible for the disasters plaguing the series.
Damsel Scrappy: Sera until she gains Atma powers.
Epileptic Tree: Satan in the second game states that a "heretic is trying to destroy the world." Fans theorize that he's referring to either Aleph from Shin Megami Tensei 2 or the Demi-Fiend from Nocturne.
- The Seraphim appearing in the second game really don't help any. Expecially since one of them - in a factory - says "This is not the factory I knew...". Guess where he was found in the second Shin Megami Tensei game.
- Serph have a striking physical resembelence to the protaganist from Persona 4. That can lead to some pretty horrifing conclutions.
- Brahma has something akin to the Amala Drums on the heads of his various forms. Let that sink in for a minute.
Fashion Victim Villain: Margot Cuvier's outfit wouldn't look out of place in Lady Gaga's wardrobe
Game Breaker: The Null Attack skill nulls everything except Almighty attacks. This makes you effectively invincible for 90% of the game as only the last two dungeons have random encounters that make use of almighty attacks and none of the storyline bosses use almighty as their main form of attack. It won't help you against the bonus bosses though since they just love their powerful unique almighty attacks and the Demi-Fiend will rip you to shreds on his first turn if you dare to have immunities equipped.
Les Yay: Pretty blatant in regards of Argilla and Jinana. Heat even Lampshades it by complaining about how she's upset about her "girlfriend". This was due to her being forced to kill a frenzied Jinana.
Magnificent Bastard: Jenna Angel is pretty much at the center of every important event in both games. Taken to its logical conclusion in that she is both Sera's mother and father.
Memetic Molester: Khumbanda in the second game.
Memetic Mutation: "I do not comprehend." Gale's Catch Phrase, often used humorously to ridiculous and/or incomprehensible events.
Moe: Sera.
Most Wonderful Sound:
- The sound of the karma meter going up after battles, especially after getting a ton of Atma Points.
- The Demi-fiend's death scream in the first game (which, given Nocturne, is the only time it's a good sound) and all the sounds Satan makes while dying in the second game, including his scream and the solar data leaking out before he explodes.
Narm: Cielo's Jamaican accent. It was intended to emphasize the friendly, outgoing disposition of the character, but most people just found it a little too ridiculous.
Rescued from the Scrappy Heap: Sera and Cielo.
Scrappy Mechanic: Berserk Mode in Digital Devil Saga 2, which happens during higher numbered Solar Noise phases. You can't use magic or items, and everyone becomes a Glass Cannon. The only thing you can do is use physical attacks or wait a turn, resulting in Critical Or Death battles. Fleeing is also an option, but Karma points get more than doubled if you win.
- Thank god fleeing isn't just an option, but has a 100% guaranteed success rate in Berserk Mode. Also, the developers applied Fridge Logic to the idea of only being allowed to use physical attacks, so your characters ignore enemies' physical resistances and immunities, allowing them to slaughter enemies they wouldn't even be able to TOUCH with physical attacks normally.
Signature Scene: Despite being a sidequest that has nothing to do with the main story and requires slogging through a large part of a New Game+ to get to, the Demi-Fiend's notoriously difficult boss battle in the first game is one of the most well-known parts of the series.
That One Boss: Cerberus in the first game, Meganada in the sequel. If you beat Meganada, even just barely, the final boss will be cake.
- Let's not forget Ananta. It gets 7 actions per turn, hits you with Dekaja, boosts itself through the roof with Tarukaja and Power Charge, and is smart enough to attack the same person constantly rather than spreading out the damage. Not to mention that it likes starting every turn by casting Sonic Wave, Stun Wave and Dream Haze in succession. And if you even try to use a Void Physical ability, it rips of Mudo and Mudoon for every attack. No elemental weakness either.
- Even for Bonus Boss, the Demi-Fiend takes this to a ridiculous extreme.
Tier-Induced Scrappy: Cielo in the first game, due to his iffy stat distribution and weakness to all status ailments. This is possible to fix with Null Ailment, but this is usually only obtained very late in the game. He is Rescued from the Scrappy Heap somewhat in the sequel due to better stat distribution.
Woolseyism: Mostly kept to name changes: the Assignments became the Vanguards, the Merrybell became the Maribel, "Mick The Nick" became "Mick The Slug", and so forth. Strangely enough, they didn't change the names during cutscenes: Gale's map of the Junkyard displays all the original names of the Tribes and Tribe leaders.
- They named one of the Mantra (skill-teaching equipment) "Wikipedia" as a joke.