Dark Magic

Dark magic, also known as the Dark Arts or Destruction, is the school of magic that studies shadow magic, necromancy, and the destruction, damaging, or weakening of beings and objects.     
Mages skilled in dark magic are known as dark mages, shadow mages, black mages, or necromancers. 
Also: Destruction magic or Black magic
Dark Spell Types: 
Weakness – To cause weakness or vulnerability to any physical incursions or a specific type of magic, such as weakness to fire, ice, or psionics.      
Drain – The draining down of a targets energy, magic, or any skills or attributes they may have. The effects of drain spells are often quick acting and eventually wear off.  
Degenerate – To cause a degeneration of health, attributes, or skills. These spells act on the target over time, with a more long lasting effects.
Deteriorate - To cause a degeneration or corrosion of objects such as weapons and armor. This may rust, warp, or diminish them in some way. 
Damage – To cause direct physical damage to people or objects. These can also maim or cause conditions or ailments in the target, or render things grotesque.   
Poison – Spells that inflict various kinds of poison.  
Paralyze – A spell that paralyzes the target temporarily, or for an extended period of time. 
Petrify – A spell that turns the target to stone or mineralizes them temporarily or indefinitely.    
Disease – A spell that causes a disease in the target. With enough intensification of the spell, diseases can cause temporary outbreaks or plagues.      
Corrupt – To corrupt the target's willpower into carrying out evil acts of greed, hate, hubris, etc. or to cause megalomania or villainous behavior.    
Death – To kill or destroy a being or object serving as the target. Death spells wither, disintegrate or can melt the target.   
Shadow – The use of shadow magic that uses anti-aether from the anti-matter universe, in which the caster transmutes into smoke or shadow, and casts shadow spells.     
Necromancy – The magic of raising the dead, or achieving various undead states, such as wraith and shade forms, zombification, vampirism, and lichdom.  
*Many dark mages also contrive ways to use absorption magic, albeit drain is more efficient, requiring less energy.