Soul of the Warrior

Soul Crystal, item level 30. Equip level 30, MRD WAR.

From 160 Pride and Duty (Will Take You from the Mountain).

From quests

160 Pride and Duty (Will Take You from the Mountain)Reward

Upon the surface of this multi-aspected crystal are carved the myriad deeds of warriors from eras past.

Other databases

Eorzea Database (the official one, on The Lodestone)
Console Games Wiki
Garland Tools (vendors, crafting, drops)