It always struck me weird how vicious Tanya was in battle when most of the time, she's almost stoic except when it came to her career prospects. But then I remember, Tanya's previous self stated that she was apathetic, had a lot of mental complexes that would fit with ASPD, and the only things that kept Tanya leashed in her previous life were the rules of Earth society and the rewards that came with obeying them. In the battlefield, where such rules get thrown out, her restrained nature, added with the fact she has to pray in order to use her Super Prototype computation jewel to survive (which pisses her off even more), and you get The Devil of the Rhine that is Tanya.
It's worth mentioning that World War I was notable as the first "industrial" war. Tanya was the pinnacle of industrial efficiency, so simply turned it to the prosecution of the war.
At first, Los!Los!Los! sounds like what a patrioticwar maniac would sing, with verses of how they seek the blood and gore of the battlefield and their enemies. That is until the last line of the song. "With an explosive sound that can even drown out their lingering hatred". This is the realization that Tanya's brutal tactics are for one reason only: to decimate their enemies so much that the Cycle of Revenge can't continue, because as she says in episode 12, people are so influenced by their emotions that they refuse to listen to reason and logic, that their desires for such must be quashed entirely. The fact that this line is said in a tired manner shows that Tanya likes war just as much as any other sane person does, which is not very much.
Tanya is very loosely following the career of Rommel. An energetic and demanding 2nd Lieutenant experiences early success against an unprepared enemy of the early French/Dacia. She then is wounded and goes for more schooling, returning to a different front with an elite unit. After success with the elite unit, she takes a strategic role (although Tanya remains fighting while giving her opinion) and the armistice happens. Then she goes to North Africa to continue the fight against the French.
(Anime and Manga only) Tanya is often mistaken to be even younger than she already is. She grew up in a poor, rural orphanage with little available food for its young occupants, and thus did not get the nutrition she needed despite her best attempts to secure food for herself. Children who repeatedly starve during their early childhood will have permanently stunted growth due to their malnutrition, and will remain small throughout their entire lives even if they receive enough nutrition later.
One of the constant bits of humor is how Tanya will completely misinterpret others' actions and reactions, and try to influence people to do one thing while actually influencing them to do the opposite. As a present-day salaryman, he fully admits to being unable to connect with people and suffered/enjoyed many ASPD characteristics, and that is for the first society he grew up in. He's a modern day man effectively going to another country centuries into the past, having relatively no time to learn, no motivation to adapt properly, and is unable to account for how being a young girl impacts how his various proposals are perceived. Of COURSE Tanya would read and give social cues the wrong way!
The plot circulates around a suggestion Tanya's previous incarnation made to "Being X" upon explaining the reason of lack of faith in the world and how to restore it, prompting "Being X" to test out the theory of "Faith through Hardship" with Tanya as the test subject. If it actually turns out as a legitimate success and manages to reform Tanya's faith, what's stopping "Being X" from applying the "Faith through Hardship" approach on a global scale afterwards?
The anime has "Being X" actually state that the population of Modern Earth alone is too much for it to handle as it is. It makes one wonder what this being has in mind for those it can't handle. Brrr...
Global? Try multi-dimensional! (It did send Tanya's previous vessel's soul to a whole different world after all. How many worlds and realities is "Being X" actually in charge of again?)
Considering the Gods Need Prayer Badly trope, one wonders what would happen should Being X actually fail? Will he just stop maintaining the worlds he's in charge of? If worship is the equivalent of food to Being X, and the "rules" of the universe, whether physics or magic, are designed and maintained by Being X, what will happen to all those worlds if he decides to quit? At best, the "machinery" of the world manages to continue without anyone maintaining it for some time. At worst, reality itself may break down.
The salaryman who became Tanya was an adult who was forced to become a baby, the age period during which humans are unable to control their bladder and bowels, require others to change their diapers and clean them up, and need to be potty trained. Even after they're potty trained, children can still get an occasional "accident" until the age of 7 or so, at least while asleep. What makes this truly bad is that it's shown that Tanya kept the self-awareness from her life as the salaryman, meaning she was fully aware of her "dirtying" herself and being dependent on others to clean her up, exposing her private parts in the process. For a person with an adult mind, this is one of the most humiliating things they can experience, and she had to experience it for years.
There's also the thing that being mentally adult (and keeping all experience from previous life) she's aware of sexual needs and certainly casually gratifies herself. This comes off as real creepy.
