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The Surge is when a Sorcerer's Magic discipline is set. Though little is known of the Surge, it is implied that when it finally occurs in a Sorcerer, they are normally unable to utilize magic differing from their chosen discipline. So when a Necromancer experiences their surge, they are rendered unable to use Elemental magic should they have trained with it before, however it is presumably possible to learn and use other Adept disciplines. However, Skulduggery has said changing magic after the Surge is not impossible, it is extremely rare. In this case Skulduggery is a perfect example as he displays great skill in Elemental magic and Necromancy and seems to have a very extensive knowledge in nearly all types of magic (as when he sees Darquesse take on The Jitter Girls, when afterwards he said something along the lines of: "I've seen every type of magic, but nothing like that" and how he immediately recognized the Unnamed Warlock simply by watching him heal a wound from Skulduggery's revolver) and quite possibly how he's able to use symbols to either create a reflection or activating his Facade. however, a possible side effect is a multiple personality trait (as when Skulduggery Pleasant uses Necromancy, he becomes Lord Vile), this is possibly like discovering your own True Name like when Valkyrie Cain turns into Darquesse. Interestingly, Baron Vengeous is capable of using Vile's armour even when he has passed his Surge. This is due to the fact that Baron Vengeous uses a form of adept magic to create a protective cloak underneath the armour, preventing the armour from consuming and utterly destroying him. This is further explained as to why Necromancer magic is housed within objects, to control this power and prevent most others from using it. People such as Melancholia St Clair have used symbol magic in order to house Necromancy in their own bodies, proving to be effective but extremely dangerous, becoming so overwhelming as to actually draining peoples life force completely.