Which is just impossible: the Origins aren't able of having children (in the traditional sense; Betas are born via a loose method of "cloning"). And it's not a mother figure to him, but more like a person he really admires. It also should be added that Word of God confirmed that Lyner's mother died when he was very young.
I suppose it's a case of YMMV, but Shurelia seems like the quintessential mother-figure to Lyner to this Troper until their relationship changes drastically in Phase 3. Her converations regarding Lyner's life and choices she has with Leard, the way she's guided and watched over him, and especially the conversations she has with him, and loving/nurturing tone she takes with him, notably in the scene before she uses the ./SUSPEND Hymnos, all point heavily to this.
To put it simply, Lyner's mother died when he was just a baby, and Leard, blaming himself for it, decided to become stricter on his son due to that. However, Shurelia pretty much served as a mother figure to him, and in both the Toukousphere and the Ar tonelico 3 light novels, she even revealed that she was the one who took care of Lyner when Leard was too busy to do it himself. She sang him lullabies, fed him milk bottles and even changed his diapers. You all can guess the embarrassment he got when Shurelia blurted this right in front of Misha and Aurica.
A heroine sings a song from a Hymn Crystal. Sometimes these songs are played over certain story battles. The Fridge Logic moment? You can use the girl that's singing the Hymn in the same battle, which effectively means the girl is singing two songs at once.
Justified because the Reyvateil simply sends some kind of signal to make the Tower play the song she is imagining as long as she can keep concentrated on the feelings that form it. In other words, the Reyvateil just sings at the start of the song, and then, the Tower takes on the role of maintaining the song and its functions for as long as the Reyvateil can keep her concentration on these feelings.
But that means she's concentrating on two songs at once.
Which is not impossible, hard, yes, but not impossible.
Also the cited reason why people in the Wings of Horus can't get to Platina. They'd have to pass the Blastline. The Blastline is past Platina, and not between Platina and the Wings Of Horus.
The Blastline is the cited reason, but actually, it's because the Frozen Eye shoots electrical discharges that no airship, besides the ones in Platina, can withstand.
There are a fair amount of things stated repeatedly in-game or in the background materials that define the world, the plot, and the characters, but don't seem to be actively true or upheld in the actual story. For example:
It's stated in several places that the Origins, and especially the Administrator, are essentially thought of and worshipped like living Goddesses. However, within the actual course of the game, Shurelia is treated comparatively 'casually'. The people from the lower third of the Tower don't seem to even KNOW about her or most of the true workings of the Tower, and not a single one, including folks from Tenba, EVER mention her in-game, choosing instead the more...::ahem::...questionable and superstitious religious tomfoolery of the Elemia Church. And the people of the middle and upper sections of the Tower essentially treat her like an important and well-respected leader and dignitary (which she is), and a treasured Reyvateil.
The supposed "Reyvateil Prejudice" that is constantly stated to run rampant, is so integral to the Tower's and several characters' backstories, and supposedly makes Lyner's treatment of Reyvateil's so noteworthy...doesn't really seem to exist in the actual game.
The people of Platina (where Lyner's from) treasure Reyvateils, acknowledge and care for them as people and equals, and respect their role in Tower life.
The Teru Tribe don't even really seem to utilize Reyvateil's, posessing some form of Song Magic themselves, but generally seem to follow Platina's lead.
They don't because Terus have their own form of magic, which has no relationship at all with Song Magic.
Other than the ONE asshole who gives Claire some grief over her bar (and keeping in mind that, by all accounts, everyone else in town seems to love her), there's not a single sign of Reyvateil prejudice or hatred in the conventional cities (Karulu, Nemo, the residential sections of Firefly Alley, etc.). According to the few conversations you have on the subject, most people seem disgusted by Tenba's activities.
In the lower Tower in general, 99% of Reyvateil's belong to Tenba or the Church (by dint of needing Diquility). By all accounts, the Church treats them with respect and as partners rather than tools (and any exceptions are because of the conspiracy and Falss being an evil douche). Tenba is, well, Tenba, and even that's implied to because Bourd has replaced most of the standing armed forces with his own faceless stormtrooper goons who are as ruthless and despicable as he is.
Just because the game doesn't show it, it doesn't mean that it doesn't exist. This is specially noticeable in the stories of the Spica and Claire Hymmnos Musicals, and in the Drama CDs for Aurica and Misha, in which we see the mistreat of several Reyvateils, and the cruel treatment that's given to them.
Related tangentially to the above, since she was mentioned: How and/or from where does Claire obtain her required supply of Diquility or similar products? Does she just buy them, because reading between the lines in the game and background materials seems to suggest ordinary Reyvalteils don't have access to them? If she DOES buy them herself, then why aren't there a lot more 'free' Reyvateils who do the same?
She buys her supply of Diquility, but since doing so has such higher costs, most Reyvateils prefer to be attached to Tenba or the Church. In fact, there are more free Reyvateils in Sol Ciel, but we simply don't see them during the game.
Why does the upper Tower keep the lower Tower in the dark about so many things that are vital to the continued, peaceful existence of their society? Or, if it's not on purpose, why is the lower Tower so ignorant of what you would assume to be essentially passed-on information? You'd think keeping the people of the Tower informed as to Mir's existence and the need to quell her (something everyone north of the Silveplate knows) would be of paramount importance, and would have prevented most if not all of the game's issues from ever occuring.
Falss and Bourd don't serve as examples? This was the way that Shurelia chose to avoid the repetition of further disasters from the humans, given that their arrogance and stupidity from having so much power at their disposal was the cause of both the Grathnode Inferia and Mir's Rebellion.
Why does the Star-Singer need to sing constantly, her entire life-long, without, apparently, ever being free to do anything, leave ever, or associate with anyone? Misha is out of commission for MONTHS upon months of complete inactivity, with Mir's agents and centuries woven schemes working from all sides to awaken and free her, and even then they only BARELY sort-of succeed thanks to Ayatane being a mole in his/Mir's decades' long gamble.
How, exactly, DOES Misha (and the previous Star-Singers) sing and cast the "Seal Mir" Hymnos non-stop? Other Hymnos, to say nothing of standard Song Magic, take MP/exertion to sing constantly, and Hymnos in particular seem to cause physical and emotional exhaustion. While Misha IS a special Beta-type, this doesn't seem to effect any other song magic or Hymnos she uses.
Because Hymmnos Extracts work differently from standard songs due to being programmed in an specialized way, while all of the Song Magic are simple expansions of an feelings -> energy conversion program. Also, Star Singers only need to sing for 30 years, after that they are released from their duties and replaced by a new one. Likewise, after Misha stopped singing, the wave inertia took care of keeping Mir's seal for some more time, up until the remains of the song's effect disappeared and the seal weakened enough for Mir to start acting up again.
Also related to the above, if Mir is sealed away and put into deep slumber, how the heck does she continue to spawn hostile viruses, corrupt guardians and other areas of the Tower systems, and recruit people to her "cause". This especially goes to question in Ayatane's case since she would have been completely sealed when she supposedly instilled him as a sleeper agent.
In Ayatane's case in particular, no one, or at the very least Shurelia, was ever able to sense or detect anything abnormal about his make-up considering he's essentially a materialized/flip-flop converted Virus?
First, because her will permeated through the Tower's systems and through Beta-6D, which allowed the creation of corrupted data and viruses while she was still asleep. Any other reason why no one saw viruses as powerful as ELMA-DS until her awakening started? Also, it has been stated that Shurelia has no access to the SH Server, nor she can analyze flip-flop conversion data unless she knows for sure that the target she wants to analyze was actually taken from the Binary Field and made to manifest in the real world.
Another factor is that the Star Singer is not responsbile for sealing Mir by herself. Tastiella/ The Cresent Chronicle does the bulk of the work of keeping Mir's body sealed and her mind asleep. Chronicle Key reinforces it. Think of it like a electrified barrier: Cresent Chronicle is the barrier itself while Chronicle Key powers the barrier. It has a back up power source in case the Star Singer is unable to sing but this a Dangerous Forbidden Technique. Tastiella is mortally damaged because of the events of the game. At that point keeping Mir sealed is no longer an option.