These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Swilium is one of the world's most efficient thieves, and does so without ever taking a life.
Moe: Invoked in-universe. In one party conversation, Val jokes that she, Layla, Sam, and Dawn qualify as this.
Moral Event Horizon: If he hadn't already crossed it before, Jonathan's Moral Event Horizon came when he ordered his guards to..."unwind" with their prisoners (including Sam at the time).
There are many points where Vilhelm may have crossed it...
Trying to repurpose Blaze, Hydro and Lightning as super-soldiers against their will.
Attempting to convert Dr. Ulrich into one of his cyborg lieutenants, ending with her suicide.
Offering to "modify" people who misbehave in his class.
Going on a mass-abduction spree, butchering and experimenting on innocent people to create his cyborg army.
When they were still together, Helena once dared Talan to wear a dress for her in private. She crossed the line when she took pictures and posted them on the Internet for all to see, driving Talan nearly to suicide. Upon learning this, Lightning vowed to make her pay.
For Jane, she drugged and raped James to have his child, only to isolate herself from him and later tell him that Jackson was stillborn. She believes she has long since crossed the horizon, though she is trying to redeem herself through her work.
Warpen attempting to force himself onto Val.
Terminus casually wiping out a small town with a wave of her hand.
Alice certainly counts; though outwardly tough, she's clearly more vulnerable around her friends. She also lived in a hellish, irradiated wasteland with her family for most of her life.
Alexei (no pun intended). He has had multiple close brushes with death, and most of his family is dead; the latter is part of what drives him to his Knight Templar tendencies, making him double as a Woobie, Destroyer of Worlds.
Surprisingly, Talan qualifies, given the revelation about the incident Helena put him through—to the point of being borderline suicidal. Clearly, he's gotten better, though.
As a Living Emotional Crutch for James, Lily provides a lot of emotional stability for him. She does, however, show signs of vulnerability after she talks about her past. Her mother was horrifically abusive, but it just ended up inspiring Lily to be the nurturing mother figure she never had.
Victoria has had a comically dysfunctional childhood, spending literally all of her life (up until age 23, when she first arrives at the Academy) never knowing anyone else aside from her parents and her magic teacher. No wonder she became so attached to Mikoto so quickly...
Blaze has trouble showing her pain, coming from (and rejected by) the same projectthat created Lightning—hence her (albeit fleeting) resentment of Layla. She also mentions that she nearly drowned in a huge flood during a hurricane when she was 13, and it's only because of Hydro that she's still alive.
Stoic Woobie: James, easily. Power Academy is his life's work, and he fears he will have nowhere to go if it fails—and it's already in danger of failing. It's not until he opens up to Lily that his inner turmoil is made apparent. His unpleasant past with Jane only increases the woobie factor. And now his life is on the line thanks to a Deal with the Devil he made to get the school built on time.