Fiendfell

This sword has a slender, curved, single-edged blade of gleaming bright steel. The blade is is razor sharp and exceptionally well-crafted, with a leather-wrapped handle that follows the curve of the weapon. The silver-plated circular guard is inscribed with elven scrollwork runes.

Fiendfell was the sword of Saint Arwyn Elsiter, one of the founders of the Pilgrim Knights. A tassel of silver pegasus mane hairs, taken from Arwyn's loyal steed Cuinor upon its death, hangs from the pommel. For a long time, the sword was a prized heirloom of House Elsiter, but it was stolen in the chaotic years after the empire fell.

While attuned to the sword, you have a +2 bonus to attack and damage rolls with Fiendfell, and it can be used as a holy symbol. When you use Divine Smite on an attack from Fiendfell, all damage dice dealt by the attack explode (as long as you roll the maximum number on any of the dice, you get to roll it again and add it to the total).

Additionally, you can hold the weapon aloft and cast Spirit Guardians, summoning a flock of tiny radiant pegasi. Once you do this, you cannot do so again until you finish a long rest.