Av2:Earthspike

Earthspike is an earthbending ability that creates a one block tall spike of earth on the block in which earthbender is facing. It only works on earth blocks, such as stone, grass, dirt, and most ores. It does not work on diamond ore, quartz ore, netherrack, stone bricks, or obsidian. It is a good offensive ability that can be used in numerous ways.

Unlocking this ability requires a tier III scroll.

Level II
This upgrade increases the strength and damage of each spike.

This ability upgrade requires a tier III scroll.

Level III
This upgrade increases the damage and strength of the spikes. Spikes are now created in a line from you to the location your cursor is pointing add. This adds the ability to attack from a range.

This ability upgrade requires a tier IV scroll.

Level IV
 As with all other abilities, there are two choices for Mine Blocks' level IV upgrade.  Tectonic Tear: Create a field of earthspikes where you're looking and shoot a row of earthspikes in that location.  Tectonic Tear is an offensive ability that creates a row of earthspikes that move in a singular direction. This earthbending move has a range of about 20 blocks. Upon hitting an entity, the earthspikes will send them flying into the air. This upgrade is recommended for earthbenders who want to add another offensive skill under their belt. This upgrade requires a tier V earthbending scroll. Cataclysmic Capture: Create a ring of spikes around you or where you're looking. Cataclysmic Capture is a good mix of offense and defense. You can use it to serve as a temporary wall or you can use it to trap enemies. Upon hitting an entity, the earthspikes will send them flying into the air. This upgrade is recommended for earthbenders who want to balance offense and defense. This upgrade requires a tier V earthbending scroll. 

Mechanics
Holding down right-click while having this move activated charges up the earthspike. The longer you hold this down, the larger the spike. This can be incredibly helpful if you want to dole out big damage quickly.