Av2:Mine Blocks

 Mine Blocks is an earthbending ability that breaks blocks directly in the direction that the earthbender is facing (creating something that looks like stairs). 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. Its a utility ability for exploring caves and going underground, easier and faster. It is also good for hiding against your opponents and tricking them.

This ability requires a tier I scroll to unlock.

Level II
This upgrade lets you mine out even more blocks. Digging range is increased.

This ability upgrade requires a tier I scroll.

Level III
Fortune level I when mining! Even longer digging range.

This ability upgrade requires a tier II scroll.

Level IV
 As with all other  abilities, there are two choices for Mine Blocks' level IV upgrade.

 Soul of the Badgermole: Can m ine very far, with level III fortune

 Soul of the Badgermole allows you to create really long tunnels for fast underground exploration. It also gives the ability a fortune III enchantment which is great for gathering extra resources in your way down or while mining ores. It's a balanced path because it mines really long distances and has fortune III.

This upgrade requires a tier III earthbending scroll.

 Pluto's Greed: Mines out ore veins with level IV fortune

 Pluto's Greed lets you mine out entire veins of every ore in its path. It adds fortune IV enchantment too  which is extremely beneficial when it comes to mining resources. Compared to Long Tunnel, this upgrade is recommended to earthbenders who want to benefit from the level IV fortune aspect. This upgrade requires a tier III earthbending scroll. 

Mechanics
Digging straight down creates a direct hole downwards instead of a stairway. This is helpful for stripmining or evading an attack by going underground.