Shadowcraft - LOTR The Third Age

After you complete all of Moria you'll be rewarded with an Elfstone of Fell Shadow which works much like the Elfstone of Nimble Crafting. When you equip the Elfstone of Fell Shadow onto one of your team members you'll open up the 'Shadowcraft' line of abilities when you scroll down during a battle.

The last similarity this Elfstone shares with the Nimble Crafting one is that you won't need to always have this equipped to use the abilities it teaches you. You'll only need to wear it when you want to level up Shadowcraft and learn new abilities.

One thing that's different about the Elfstone of Fell Shadow is you'll learn the abilities it teaches you much faster than the Nimble Crafting Elfstone. The downside though is they all consume a lot of AP - the cheapest you can spam being unlocked second which costs 30 AP.

Here is a list of all the abilities you can learn with the Elfstone of Fell Shadow. It took me about 1/3 the time to learn all the abilities with it as it did the Crafting Elfstone.

Dispel - Removes enemy enhancement (single target)
5 SP to learn this ability.

Whip of the Master - Protects your party against Slow
10 SP to learn this ability.

Silence - Prevents an enemy from using any Spirit Power attacks for a short time
15 SP to learn this ability.

Crippling - Slows the attack rate of an enemy
20 SP to learn this ability.

Drain Health - Drains health from the enemy and returns it to the caster
20 SP to learn this ability.

Black Speech - A powerful Spirit attack
20 SP to learn this ability.

Fear - Paralyzes a single enemy with Fear for a short amount of time
30 SP to learn this ability.

Wheel of Fire - An area of effect damage over time ability that does a lot of damage
50 SP to learn this ability.