Dwarf Fortress - not DnD, not might and magic. It is very special setting. And need only special mages. Fierball-shooting and spiritshield-creating wizards from RPG is forbidden.
Druid - magus, who make sapient creatures mindless and mutate them into trees. Needs trees sphere and dream of bringing lasting peace to the world.
Medium - magus, who can summon ghosts of historical figures. Needs sphere of knowledge and dream of seeing the great natural places of the world.
Summoner - summon bogeymans or bogeyman-like imps. Needs sphere of nightmares and dream of ruling the world.
Constructor - not reanimate parts like necromancer, but can grab corpses and parts for construct (using medical skills) from it procedure generated special zombies - Constructs. Needs sphere of blight and dream of creating a great work of art.
Animator - can make elementman from material (make special statue and animate it) and animate furniture. Needs sphere of creation and dream of crafting a masterwork someday.
Alchemist - immortal with only metal tissues and quicksilver blood. Needs sphere of metals and dream of stay alive.
Incubus/Succubus - improved version of night trolls who not married but will breed with sapient creatures. Needs sphere of lust and dream of falling in love.
Vendigo - night creature hunter, eat intelligent creatures and can control weather. Needs sphere of murder and dream of stay alive.
etc.