The Geomancer is one of the jobs granted by the Water Crystal.
The Geomancer is a quirkier job than most others. It is a job that wields bells in combat and is influenced by the world around it, allowing it to utilize the powers of the environment that they are currently in. The concept of Geomancers would make infrequent appearances throughout the series, such as being represented through Mog's dances in ''VI'' or as jobs in ''V'', ''XI'' and ''Tactics''.
The 3D remake and Pixel Remasters would buff the job by removing its key drawback: the backfire mechanic. This change alone makes Geomancer far stronger as there is no worry of punishment for spamming the Terrain ability.
The main ability of the Geomancer: Tapping into the environment around them to cast powerful magic. As such, where you are will influence what type of attack you'll get: Being somewhere like the Nepto Shrine will result in more water or ice-based attacks compared to, say, Dragon's Peak.
In the original Famicom release, if Terrain were to miss every target, the spell would backfire and damage the caster. Later versions removed this trait.
Interestingly, at least in the remake, the effects by Terrain do not have actually have elemental properities, making that aspect a non-factor. Damage calculation instead varies by ability, though they follow similar fomulas.
On a different note the remake's Geomancer features an odd quirk in one of its abilities: Magma. It can only be cast in the Molten Cave and nowhere else. Its single target equivalant, Flame Burst, does not share this quirk as it can also be used in the World of Darkness.
Bells are largely superflouous due to their lack of interesting effects + the Geomancer largely remaining in the back row. Black Mages can help to cover the lack of elemental ability.