Ice Storm chimed in. An educated mare herself, it was always pleasant to be involved with her when the subject of magic and its many varying attitudes and means came up. More than most, she understood. "Yes, but the tantabus is a different matter. It was an emotional construct given, frankly, too much awareness and ability to adapt. It has the same aetheric signature as a powerful golem, enhanced beyond reason by its connection in the dream world and Luna's investment of power into it. Luna's emotional state was connected to the Tantabus but the parameters of its creation and operation didn't necessitate Luna's emotional state remain negative to power it, since it was given enough agency to do it itself. It required a positive mental state of Luna's and her own positive aether pull to defeat, but the tantabus itself operates differently from a pony's own emotional state," she said as she popped open a book on magical constructs- a wide variety existed, not the least of which was golems. Indeed, she had been studying them closely as of late. Much different from the tantabus but they did have one element in common that intrigued her.
No matter, the discussion continued! "The main difference between your magic and its change based on emotional state and the Umbrum Aetheric is the basic facts of the magic in question," she said as she took a sip. "Take a stun bolt of magic from your horn. Your emotional state- extreme anger, protectiveness, you get the picture- may allow that bolt to become stronger as you pull more from the aether, essentially an emotional adrenaline surge allowing you to go past your basic limits the same way physical adrenaline pushes you past your physical ones. But that stun bolt can't or won't become deadly no matter how strong it becomes. Casting a spell from the Umbrum Aetheric is different. Not only does it require you to be in that negative space and cast that specific spells while within in that state. That is the largest difference between the Umbrum Aetheric- Dark Magic- and the rises and falls of magical strength and limitations based on emotion. That stun bolt will never kill. A stun bolt in the Umbrum Aetheric does not exist- it can only kill."
It was then that Ice Storm decided to rationalize Sombra'a actions. On a personal level it was just and good to understand what drove creatures to make the decisions they did. However, Ice was going a step further, and sympathizing a bit too much. It could be an issue. Rationalization was always the the first step on the road to tyranny and other forms of moral foolishness. But, here and now, she wouldn't get into a debate on flawed philosophy while she was mostly worried about this new fella. He was the real "That depends. A spellcaster with everything to lose can be just as dangerous. Extremes drive extremity and power," she said before turning the attention back to him. "How long have you lived up north, again? I'm sure you have some interesting stories to tell."
Twilight started to through the records rapidly aided by her magic. Soon- very soon, she arrived at what they needed. "Ahhh, here we go," she said as she opened up the page with his student history. It had some pictures, academic records, disciplinary records, class history "Oooh, okay. Yes, as expected. He was a top student- a little before my time. Even caused a snowstorm once. Powerful magic..His mother was a professor? Oh..." she thought for a second "Oh! I remember her from the logs," she read further. "This all makes sense. Come Ice, read what happened to him."