Geomancer

The Geomancer (also known as the Wiseman) is a recurring humanoid class in the Disgaea series first introduced in Disgaea 2: Cursed Memories.

The Strider in Disgaea 1 had a similarly named final form Geo Master. Striders are precursors with Geo Change as well as Cannon.

Characteristics
Geomancers are old men with the power to control land formation via the Geo Crystal on their foreheads. They are hard to deal with, as they are always looking for ways to make life harder for other people solely for their own amusement. This stems from Geomancers actually being far younger than they appear, having had their youth drained by their Geo Crystal. If one understands their Geo powers, they are nonetheless a strong ally.

Disgaea 2: Cursed Memories
In Disgaea 2: Cursed Memories, Geomancers are unlocked by doing a Geo Chain of over 500 and then passing the "Make an Old Man" bill in the Dark Assembly. They are adept at healing and Star magic. They also have numerous abilities that deal with Geo Symbols.

Disgaea 3: Absence of Justice
In Disgaea 3: Absence of Justice, Geomancers are unlocked by having a level 20 Cleric/Clergy and Martial Artist/Fight Mistress, then passing the associated bill in the Dark Assembly.