History:
Calius an old blacksmith in the city of Iaurinum on the southern coast of the Aggelos Empire. Calius worked his trade in the Foreign District in this sprawling metropolis, the nastiest most criminal-filled part of the city. He would make illegal weapons for whoever asked no questions asked. When one bright spring day with the sun shining through his front window Calius had a surprising guest, a very graceful attractive but not exactly beautiful woman comes into his shop. Dressed in armor of the finest quality he had ever seen. She stepped forward and addressed him by name, telling him she wished him to make a sword for her, one unlike any he had ever made before. She placed a scroll on the counter and a large bag of gold. She explained in a tone that prevented the rather shocked Calius from turning away that the scroll contains exactly what he will need to do to make this blade and he was not to deviate from the specifications. He gave a faint smile when she leaned forward a mere inch from his face and repeated that he was not to deviate, should he choose to do anything other than asked she will be most displeased.
What she gave him was nothing like how he had ever made a blade, and took him time to gather what she asked for. Nothing really extraordinary really just better quality than he was used to. He took his time and made the finest sword he had ever made.
When she returned exactly the day after he had finished, she inspected the blade and was pleased by what she found.
She had him come outside into the morning sun and told him to raise it above his head and call on Sif to bless the blade. Taken aback he paused, she turned and looked at him with her eyes suddenly glowing with a faint golden light. He quickly did as he was told and the blade burst into fire melting away the blade and leaving only the hilt. Terrified he dropped the now useless blade on the ground and fell back onto the ground.
She stepped forward and picked up the hilt and handed it to him, call on the blade she says. He slowly stood and held the hilt in his shaking hands and called on the blade as best as he could, with a sizzling sound and something akin to the sound of sackcloth being cut a blade appeared with a bright fiery glow like the sun.
She turned to him and told him that "they" are pleased with his work, she gently kissed his forehead and walked away with the hilt. From that day forward he became an avid worshipper of Sif and became known as one of the finest sword smiths in the world.
Dungeon Masters Guide Description:
SUN BLADE
Weapon (longsword), rare (requires attunement)
This item appears to be a longsword hilt. While
grasping the hilt, you can use a bonus action to cause a
blade of pure radiance to spring into existence, or make
the blade disappear. While the blade exists, this magic
longsword has the finesse property. If you are proficient
with shortswords or longswords, you are proficient with
the sun blade.
You gain a + 2 bonus to attack and damage rolls made
with this weapon, which deals radiant damage instead
of slashing damage. When you hit an undead with it,
that target takes an extra ld8 radiant damage.
The sword's luminous blade emits bright light in a
15-foot radius and dim light for an additional 1 5 feet.
The light is sunlight. While the blade persists, you can
use an action to expand or reduce its radius of bright
and dim light by 5 feet each, to a maximum of 30 feet
each or a minimum of 10 feet each.
