Blueblood Sword

The Blueblood Sword is a Straight Sword in Demon's Souls.

Availability
The Blueblood Sword is created by giving Blacksmith Ed the Pureblood Demon's Soul, which can be created from an un-upgraded Broken Sword. As with the other Boss Soul Weapons, Blacksmith Ed must have been given the Red Hot Demon's Soul beforehand.

General information
While it has some minimal scaling in Strength, Faith, and Magic, the Blueblood Sword unusually scales with the Luck stat. Scaling benefits start slowing at around 25-30 Luck.

Usage
The Blueblood Sword can also be buffed. A buff with Light Weapon will drastically increase its Magic damage. Since a Blueblood Sword build cannot use Cracked Talisman of Beasts, Cursed Weapon is not preferable.

Increasing Magic is therefore also a valid option for a Blueblood Sword build using Light Weapon.

Trivia
An exploit was found by the Souls Glitchcord that allowed anyone to gain an absurd amount of level points on the Luck stat. This was achieved by using the consumable Gold Coin, right before interacting with The Maiden in Black to level up. The Luck stat would, once on the level-up screen, increase by hundreds within seconds. This glitched leveling would then be confirmed by exiting the level-up screen; it would automatically apply the levels to you without consuming any souls. This was showcased by popular Soulsborne YouTuber ymfah in his "How to Break Demon's Souls Remake" video.

The bug was later patched in v1.004.000.

Меч голубой крови