From The Heretic Knowledge Vault
Magic pertaining to the dead, particularly resurrection of the dead. The only time we've seen it used (by the Anilis-supercharged Ian), it didn't work well, to put it mildly. Random snippets elsewhere in the story suggest that this wasn't an isolated occurrence and that Necromancy is one of those things you do not mess around with.
He uses it more successfully in a subsequent encounter with a band of trolls, who have just executed one of their own kind for committing what sounds like a particularly heinous murder. The resulting corpse is fresh enough that whatever went wrong when Ian used it on his sister Evelyn doesn't go wrong this time, or at least he doesn't care if the troll's body is possessed by some malevolent spirit rather than that of the recently deceased troll. From Ian's point of view, that's not a problem; it's a shock troop, and he wants to make more of them.
Research on necromancy is currently banned in Tsuirakushiti, apparently. Rena Doyel, Meji's classmate at the Sashi Mu Academy of Thaumaturgy and Conjuration, is working on a senior thesis for Professor Yukiri's class that takes the form of paper arguing that this ban, and the corresponding prohibition on time-magic research, has become archaic and unnecessary. Based on Ian's experience, however, one can probably conclude that Ms. Doyel's thesis rather misses the point.