Why is Sanity used as the game's energy system? Because Graveland, as explained in Stage 0-1, causes Sanity Slippage in ordinary people who delve into it.
Realms also use Sanity likely because they are Eldritch Locations like Graveland, while the Trials, being training programs for Evokers and Dolls, may have been made to mimic Graveland's environment.
Akaset and Juewa often bicker with each other because of a lot of overlap between their characters as sci-fi childlike girls, yet work well together. This also applies in gameplay: equipping both with Lightning skills can have Juewa supporting Akaset with row attacks with Plasma Field, and SP and attack boosts through Hyper Charge; for Frost, Akaset can act as a protector and fire Icicle Shelling, another all-hit skill that works with Juewa's multi-target skills.
Although you can encounter the Seven Deadly Sins as Mooks, there is never one named Pride. It is explained in-story that Pride was sealed by Ebony Squad, but she was notably the one Mook responsible for their many deaths despite being a crew of Badass Normals. This is exemplified with her boss form as "Supreme-Supreme"; her pride wouldn't have taken to being below any of her contemporaries after all.
It makes some sense for the baddies in each of Graveland worlds that despite being thematically based on an element, they also have it as its Logical Weakness in a Takes One to Kill One kind of way:
The Dire Forest hosts living, physical manifestations of the Seven Deadly Sins born of materialistic vices. Therefore, a good physical beating should sort them out.
The Yomi Marsh is riddled with ethereal beings. Going by Shadow- and Eclipse-related Rune names found in the Abyss Rift, the Shadow element is occult in nature, which is expected of exorcists.
The Wild Crater has plenty of furred and insectile wildlife that would make burning them easily, and even the Basilisks can be cooked underneath their stone skin.
The Star Ruins are full of robots weak to lightning because enough of it can overcharge their circuitry.
The Monsta Play is not only a stage made of paper and wood, so are its puppets and the Legion, all of which don't take well to water (or melted ice).
In the case of the Afterimage enemies, they are amorphous and likely susceptible to ice the way slime freezes, which is especially helpful when stopping their self-destruct skill. The evermoving Vast Gaze is affected for similar reasons, all the more appropriate for the story boss fight where you have to make it cool down for a talk.
The Monster of Origin is Yotsuyu herself, who also retains her signature powers over ice. The fact that she is the creator of the stage may also be another reason why all the baddies are weak to ice.
The Snow Realm is practically buried in ice, so why are all the baddies there weak to ice when they were able to resist it all that time? Remember that they are all fallen deities who were not originally based on ice and once lived in better climates; applying ice to them just tips over what remaining frost resistance they had and finish the job. The debuffs applied to them that activate upon receiving Frost attacks reinforces this.
Doing Patrols reward you "Top 100 Litoris" books, the flavor text indicating they are restaurant guides. In-game, they are used to go on Dates with your Dolls, although not all Dates involve a restaurant; this makes sense since the Evoker can also scout out potential dating spots during his patrols, which in turn translates to getting the books.
The Bond system. Present stories increase your Dolls' affinity levels, Dates net you both affinity and Key Boxes (which are opened for Emotion Keys), and Past stories can be unlocked using said keys. Present shows daily life between the Evoker and his Dolls, or rather, how Dolls are getting used to life in Litoris with help from the Evoker; they are comparably not as intimate as Dates, which are what really allows the Evoker to get to know their Dolls, including their 'locked' history, represented as Emotion Keys to be used for their Past.
Five-star part-time jobs recommend Dolls suited to that particular task, some of which are not immediately obvious:
"Homestay Review" needs people to, well, review some homes. Aurora is pretty much an expert at comforts for sleeping and lived in a castle. Ennis, on the other hand, has lived in an opulent mansion (working as a servant and mistreatment by the owner notwithstanding), got forced into a mine with very harsh working conditions, and worked her way into becoming an independent, upper-classwoman position, thus providing benchmarks for suitable living conditions.
"Jigsaw Pro" needs someone experienced with fossils to help. Gawana is suited to this in a very unfortunate way because she had been researching necromancy in order to revive her people, experimenting on animals and sacrificed countless innocent travelers in this pursuit.
"Mafia Investigation" suits Ennis since not only has she worked as an undercover spy, it's convenient because that's what she's been doing in her Present and Date stories; she gets to earn money while she's at it this time!
"Monkey Fighter" recommends Ruri, a ninja who has the agility of a monkey, if not more, which she can use to beat up the monkeys.
"Psychologist" needs someone who could restore some people distraught from going into a haunted house. Benten is a self-proclaimed exorcist who could assuage the patients' minds of possible ghosts, although it doubles as an Irony since she also has mental issues.
"Wasp Crusher" recommends Satya and Juewa, because the former once defeated armies of winged angels she would call pests and the latter was created to exterminate entire species. For a job to exterminate wasps, it's a bit overkill in retrospect.
There are three types of cards used for evoking that fit the game's astronomy themes: Astral Cards for Verves, Lunar Cards for Dolls, and Solar Cards for a guaranteed Doll summon. Verves, especially those of SR rarity and lower, are far more common to roll (along with Souls, Wisps, and Doll Shards) than Dolls, not to mention duplicates of them existing in comparison to there only being singular versions of Dolls—as such, there are as many Verves as there are stars in the sky. Dolls are summoned with Lady Shera's help so it makes sense the moon is represented for their evocation cards, but because the moon in reality reflects the light of the sun (assuming Litoris's astrophysics are the same as ours), it makes sense that Solar Cards have the full power of the sun instead of the moon 'mimicking' it, so to speak.
