Arilyn's moonblade

Arilyn's moonblade was the hereditary moonblade wielded by Arilyn Moonblade, having been passed to her by her mother, Princess Amnestria of Evermeet.

Description
The sword and its hilt appeared antique. After Amnestria left Evermeet, the moonstone in the hilt was removed and replaced by a modernly cut topaz stone. That was how Arilyn carried it for many decades. However, the original moonstone was restored to the sword in 1361 DR. There was Espruar writing on the sword, as well as wards to protect the runes against translation spells. All in all, there were nine runes on the sword, each one indicating an ability of the sword that the wielder had given it.

Arilyn wielded the sword with two hands. .

Abilities
Like other moonblades, Arilyn's moonblade burned anyone who attempted to touch the sword, and potentially killed anyone who attempted to wield the blade. However, in 1361 DR Arilyn placed a rune on the sword that removed this restriction so that others could touch the sword if needed. The sword would not shed innocent blood.

The sword was wielded by eight of Arilyn's ancestors, each of whom had left with it a special power, as indicated by a rune. The moonstone in the hilt enabled each successive wielder to grant a power to the sword over a period of time. The ninth rune that Arilyn placed granted removal of the restriction that prevented people from touching the blade and getting burned; it is implied she did this for Danilo Thann, who had been burned when he carried the sword to her.

The different powers were
 * Rapid strike (the sword could strike abnormally fast)
 * Immunity to fire
 * Warning glow (glowing blue when danger approached)
 * Silent warning (humming with silent energy when danger was near)
 * Dreamwarning (waking the wielder with a dream when danger approached)
 * Illusion (projecting illusions to disguise the wielder)
 * Elfgate (controlling a portal between Faerûn and Evermeet)
 * Elfshadow (calling forth the shadow of the wielder; the shadow could fight and kill)

History
Dar-Hadan was a mage who wielded the moonblade. He was the one to imbue the sword with a warning glow.

Dar-Hadan's daughter Zoastria wielded the moonblade. In 867 DR, it was recorded by Ventish of Somlar that she was searching for her twin sister Somalee, who had vanished on a voyage at sea, and that she often used the moonblade's elfshadow ability.

The moonblade then passed to Xenaphor, the oldest child of Zoastria's youngest brother. Xenaphor was once attacked by a red dragon; it was he who made the moonblade confer immunity to fire on the wielder.

Thasitalia was a solitary adventurer, so she gave the sword its dreamwarning ability. She was Arilyn's great-aunt and passed the moonblade to Amnestria.

Amnestria inherited the moonblade from Thasitalia, who had been away from Evermeet. Amnestria fell in love with a human, Bran Skorlsun, and bore his child (Arilyn). She imbued the sword with the elfgate ability to control a portal between Evermeet and Faerûn in an attempt to "unconsciously" combine her two worlds. The elves had moonblade dismantled; Amnestria carried the sword into exile and Bran was forced to carry the moonstone so that they could never meet each other again.

In 1361 DR, Kymil Nimesin attempted to obtain the moonblade for its elfgate ability in order to take over Evermeet. He gained control over the sword's elfshadow ability, creating the Harper Assassin that mysteriously killed people around Arilyn. The moonblade was restored and the portal opened. However, Arilyn arrived in time to defeat Kymil and Danilo Thann was able to move the portal to a safer location (Blackstaff Tower in Waterdeep).