Hello. I an a huge fan of elder scrolls. Have 450 hours only of morrowind, at first din't liked much ESO but looks like the game is much better now. Still like some aspects of older games, like in depth attributes, chances of spell failure while casting very powerful spells, etc. But one thing that i din't understood in ESO is "dark magic".

For those who din't played previous elder scrolls games, you can argue that most sorcerer daedra summoning skils are similar to "conjuraiton" magic school. with the big difference that no skill can conjure an weapon/armor. And that most "storm calling", similar to lighting destruction magic. But what about "dark magic"? Dark Exchange for example "materializes" crystals that take out your stamina in order to give magicka and health. Crystal shards materializes an crystal and trow it into the enemy. And daedric minefield, you can argue that is similar to "rune" spells, but i don't see anything similar to "dark crystal" spells on later games.

Since ESO happens much time before the first game, how did this magical knowledge got lost? And no one mentioned it on future books?