It had been very easy for Tyrael to forget about just what kind of magic Rathma practiced. The nephalem rarely had any reason whatsoever to use it around him.
Of course the former-angel knew the basic concepts behind necromancy. He had seen some of its proper usage from the two 'Chosen' that had battled Malthael alongside the other Neo-Nephalem. He had seen some of the worst that dabbling in Death had to offer from Malthael himself. Most of this he had forgotten as well, however. It simply wasn't relevant to his current goals, and so he hadn't given it any thought.
And really, Tyrael was well aware he had no business judging the art. Rathma's students had contributed time and time again to the wellbeing of Sanctuary. According to the nephalem himself, Balance was what truly mattered to a necromancer. Balance of life, balance of death, balance in light and dark, good and evil.
The concept was actually very similar to some of the core values of justice. Fairness, the ground between right and wrong, truth and morals...the scales always need be balanced, or chaos and revenge would reign.
Being the former Aspect of Justice, Tyrael found he could easily get behind the ideals that Rathma stood for. In theory.
They had gone to Rathma's old study for the information it held. Precious old records and recounts of events and history that could not be found anywhere else in creation. Tyrael had happily gone through it all with his nephew. It made him feel like they were close.
Currently, the former angel found himself sitting cross-legged, tucked up against a bookshelf. He was steadily going through the lower volumes, categorizing and cataloguing. Pick up a book, read a little, write down what he'd found in a notebook and place it with similar subjects.
It was rather calming work, and interesting too. While the predominant subject was of course history, there were other works mixed in too - and from various authors. Magic, architecture, art. Tyrael had found multiple of each already.
And then he'd found a book that must have been penned by Rathma himself. The cover was plain enough, a deep burgundy leather, with an image of a dagger embossed on the front. As he had done with every other work he'd found Tyrael had begun skimming through the contents to figure out what he held. The language was both legible and illegible in places, and Tyrael decided that the author must have gone back and written more several times. Some words were faded, and some looked to have been written by a different hand. Perhaps an editor? Or one of Rathma's old students?
Around the time that he'd found the first diagram of a dissected arm, the angel began to suspect what he had in his hands. He had not taken Rathma for an illustrator before. The book, however, was filled with them.
As he went through, Tyrael began having serious doubts about his mortal body. Who knew there could be so...much, inside a human? Privately, Tyrael was really quite glad that his innards were...well inside. Seeing even sketches of the human body was oddly disturbing.
He supposed it made sense that mortals were so solid, if they had so much stuff inside.
Tyrael slapped the tome shut, and set it down. Breathed a sigh. Glanced over at his nephew, who had scaled the walls in an effort to reach the highest shelves. The old nephalem flipped himself upside down with the use of that prehensile tail of his, and continued his work. A few bones floated across the room to add themselves to a growing pile. (They were stashed everywhere it seemed.) Rathma turned, and their eyes met briefly, and Tyrael looked away with a self-conscious smile.
King of the Necromancers. Right.
The next book he flipped through was about demons, and their...uses. Not that Tyrael could understand the script, but the pictures told him enough. Oddly, the material almost entranced him. Being an angel, he had never seen anything quite like this book of demons.
Sure, he knew the basics about them. But few angels had ever been willing to write down much about their hellish counterparts.
He thought that the first section might have been detailing behaviors of common demons. Strengths, weaknesses, habits and the like. Some were more detailed than the rest. He recognized the depictions of Fallen Ones, and the Khazra. There were overlords, which had several words in bright red ink - warnings perhaps? An image of a Butcher demon, and some of the havok one could wreak. Skeletons of various kinds, sizes and uses of the individual bones.
Towards the middle of the book, Tyrael discovered that all seven Evils were in the book too - with alarming accuracy. He knew Rathma had encountered Mephisto before, but when would he have gotten close enough to the rest? This book was old, too. Far too old to have been based off the recent attacks and tragedies caused by the master demons.
Had...had the evils been so active on Sanctuary for so long? Well, he had known about the Triune from other accounts. But Baal? Azmodan? Just how did Rathma get close enough to be able to depict them so accurately?
Tyrael abruptly decided it was probably better if he didn't know. Rathma had clearly gotten this far without being corrupted or possessed or anything, so he must've known what he was doing.
Probably. Hopefully.
Tyrael placed that book with the first one, and moved on.
Belatedly, Tyrael realised there were almost a dozen of these 'necromancy books.' If the first two had bothered him so, what would ten more do?
"Would you rather switch?" Rathma's voice sounded much closer to him than he'd anticipated. Tyrael looked up, and all but fell over when he realized the nephalem had (oh so silently) moved from the other side of the study to crouch directly in front of him.
Rathma raised a delicate brow, and tilted his head.
"That would...perhaps be best." Tyrael uttered, and began to push himself up. The necromancer beside him hummed, and scooped up the book he'd previously been leafing through. Tyrael thought he might have been pleased to discover that particular tome.
For his part, Tyrael was quite pleased to go back to some history books, and leave the horrors of demons and necromancy to Rathma.