Geomancer

A Geomancer is a controller that uses shapes the battlefield to their benefit. Fissure is their main control spell that creates a large hole in the ground that enemies will have to get out of. This can be powerful when combined with other tools such as a Flame Oil Flask. People at the edges may step out of the fissure by spending an RP, but then you have the option of hitting them with a Seismic Shove. 

Seismic Shove is a unique forced movement ability in that it lets you push an enemy in any direction, instead of only backwards. If you hit an enemy with it, you can toss them into the Fissure they just avoided.

Mud Wall is another area control spell that you can use. You can spend AP on it to either build cover for yourself and your allies, or create a small patch of difficult terrain for the enemies. When used a reaction, you can use the cover creating part of it to turn a potential hit into a miss or use it to make an enemy be unable to reach your allies. You can also use it in combination with the Fissure ability to create a sudden wall for when an enemy attempts to jump out of the hole.

Secret Art: Earthquake is a wide hitting spell that does low damage, but knocks enemies prone. Its main strength is the extremely long range on it and the bonus damage it does against magically created objects. The last part may not come up often, but it will be devastating when it does. Be aware that it will also destroy your own mud walls.

Finally, Tremorsense is a simple spell that lets you temporarily become aware of creatures. Useful for spotting out potential assassins, but it can also let you do things like position a fissure through a wall.