When attempting to cross the border into Cyrodiil in Bruma, most of the factions have dialogue if you're far enough alongnote i.e., if you've completed "Way of the Voice", you can use the fact that you're Dragonborn; being a member of the Imperial Legion also gets you passage, save for being the Guildmaster of the Thieves Guild and Listener of the Dark Brotherhood. However, those 2 guilds do have options for crossing - you can also bribe the border guard (like a thief would) or you can attack (and assassinate) the guards.
Many of the Necromancer characters in Bruma have the Turn Undead spell, which might seem like an odd choice for a necromancer. However, when you consider the fact that conjured and reanimated minions do sometimes go rogue or are bound improperly, it makes perfect sense for them to have a spell that makes it easier for them to deal with out-of-control experiments.
