Shaarat'doovol, the Blade of Truth

This longsword was forged in khaar'draguus, the lava pits below Sharn, and wielded by an ancient Dhakaani hero who fell in battle against the daelkyr Belashyrra. A sentience lies within the blade; it doesn't communicate with words, but while attuned, you can feel its emotions and desires. Shaarat'doovol was forged to protect the innocent from the machinations of the daelkyr, and if it feels you are serving that purpose, it can grant great power. You gain a +3 bonus to attack and damage rolls made with this magic weapon. When you hit an aberration with it, that creature takes an extra 2d10 radiant damage.

Unyielding Duty. If you have the favor of the sword, it guides you and shields you from unnatural influences. While wielding this sword, it can choose to grant you the following benefits: you gain truesight with a range of 90 feet, you can't be charmed or frightened, and you have resistance to psychic damage.

Versatile: This weapon can be used with one or two hands. A damage value in parentheses appears with the property—the damage when the weapon is used with two hands to make a melee attack.

Proficiency: martial, longsword Source: Exploring Eberron p. 224 (Third Party), Player's Handbook p. 149