Major Aldnoah spoilers ahead... /sorry for block of text and OOT, won't keep it up
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Lol. I really don't know if i can do this here but here lets start.
Both side main character...... is just bad. There is simply zero character development over two season.
That is actually not true, and you even admit it yourself later in your post.
But as per character development...
Inao can't develop to a certain extent. He is an obvious Asperger. Even then, I would say that he at least matures a bit, to the point of him being able to express his feelings (via computer interface), and taking responsibility of a squad instead of doing the lone wolf thing.
naho is cold and calculating character. Slain is emotional character. Asseylum is positive genki princess.
And that trait is taken from the first season till the end without any single change. Hell it even end up worst with how Inaho become worst as he is more or less Terminator in S2 with some of his brain eaten up by AI......which is never mentioned at all anymore in last 3 episode.
Asseylum is generally naive and spoiled, very unaware of the realities and struggles of the "real" people out there, which is partly because Aldnoah is about contrasts and dualities. She is the opposite of Rayet Areash, just like Slayne is the opposite of Inao.
Inao isn't infallible either, he almost gets his entire platoon wiped out in S2 because he simply could not foresee that Knights would start changing their tactics (more on that later, it is a major point that Knights rely on their "Aldnoah / God given rights and powers which makes them superior to all, and have a super strong sense of individuality) so drastically and start working together and using their abilities in a synergistic way.
As per the AI taking over Inao's brain .. are you sure you watched the series till the end?
It takes a major turn at episode 10 of S2 (3rd before end) with Inao being unconscious due to his wounds and the Brain interface problem which allows the AI to discuss more "openly" to Asseylum. During the final fight between Inao and Slayne, his eye interface finally overloads and leaves him without the extra abilities, and the removal of said interface is addressed at the epilogue.
But the way I see it, Inao is a great character. He doesn't whine, he doesn't rely on being a "chosen one" or mutant with supernatural powers, he is just smart and using his brain and his knowledge of physics to win. Contrarily to most Mech show, his Robot is actually the leat powerful and relies on versatility and extra agility.
Slaine the emotional one...... suddenly become smart and crazily calculating that it is shocking then suddenly in last episode he throw away all his achievement just because the princess said no to him even when the last 4 episode he just mentioned that he had changed for the people of Vers? The hell?
Slayne has been traumatized by years of abuse at the hands of the Martians, but while a slave he has also been trained as a skilled pilot. I don't see him "suddenly" becoming smart, he was just not in a position of using his skills and intelligence beforehand. Arriving in a position of power in the Martian nobility allowed him to show that side of him is all. I didn't see any contradiction in his character at the end, he always hated the hierarchic system that underneath it all was making it impossible for him to ever dream of being with the person he had been obsessed with for all these years (Asseylum), so in fact you can see three layers in the character: He plays an ambitious and opportunistic Knight using a lucky break to rise in the Martian Nobility, while underneath trying to achieve power within said nobility with the supposedly noble goal of overthrowing the Aldnoah caste system where a very few have everything based on inherited rights while the majority of the people suffers(what Harklight is all about) but underneath it all it's actually all about Asseylum. When -that- crumbles, everything is lost.
If anything, Slayne is very good at lying, both to others, and to himself.
Seylum being in the tube for almost the whole S2.... just to wake up and do even stupider things which my brain can't comprehend.
Can't say I'm a big fan of Seylum myself, but she has the "princess" role, and as an idealized and unobtainable idealist she fits the bill for both antagonists.
I found Lemrina to be far more annoying actually.
Now I found that the ending really redeemed Seylum in fact. they could have gone for the happy ending to please the fans, but they went for a more realistic and down to Earth conclusion: compromises have to be made, you can't have everything you want, it's all part of growing up. Even losing your "one true love" if it's in the interest of peace.
This is only the character here. Not yet the whole battle between Super Robot vs Real Robot with tactics.
I would even dare to said that the battle is never about tactics but more about stupidity vs people who actually uses his brain.
All those super robot users just go straight and dies like a jobber. There is simply no tense moment as we all know that Inaho is going to kick their ass for how incompetent the Vers pilot is.
That's the thing. These knights have never known defeat before (one knight has disappeared during Heavens Fall) , and they don't think it's even possible. That breeds sloppiness and overconfidence. Vers pilots are not incompetent per se, they are just imbued of a feeling of invincibility -which is technically correct in many cases-, which also stemmed from decades of being taught they were from a race naturally superior to humans and with a technology that was practically god given, making them "chosen".
As per no "tense" moment, you must have missed the dozens of deaths (not counting the Orbital Fortress falls) in combat. Even Inao is hardly untouchable: He sacrifices his Mech in his second fight to score the kill, he was about to be killed in his third fight when Slayne arrived to knock the projectile off course just in time, and he would again have been killed by Femieanne when she goes berserk without the timely intervention of the Deucalion, and we all know what happens at the end of S1, right?
In S2 again, ep 8, Inao's entire squad is saved at the last moment by the Deucalion which takes some major damage. in the process
Not to mention near the last of S2, the whole Real Robot is more or less Super Robot when their normal bullet is now able to pierce all Super Robot defense lol. i mean, the show even break its own rule.T_T
I can keep talking about how bad A/Z here but i sure as hell prefer Delta here vs that trainwreck of a show called A/Z.
I'm not quite sure what you are referring to here, but I'll leave it at that: You are obviously free to feel how you will about Aldnoah (tbh it doesn't look like you really paid attention though), but so far Macross Delta is pretty bad, at least for me.
I'm not even sure it qualifies as a Macross series at all in fact, and saying that as a huge Macross fan is sad :/