Valkyrie

The Valkyrie is a legendary sword and one of the four refined options for Necron's Blade. It is considered the berserker branch of the refined blades due to its high and. This sword is considered the best sword, both in dungeons and outside, for melee damage. It is however outclassed by the Hyperion in terms of the Wither Impact Scrolls, as it doesn't grant Intelligence, making the ability unspammable. This sword gives the greatest Ferocity buff in the game. Its Strength is considerably enough, but despite it being specialising in strength, it has less base strength than the Hyperion. However, the Valkyrie eventually overtakes it, at a maximum value of 170 strength. Overall, this is the best sword currently in the game for melee damage and the dungeon class Berserk, although it is also commonly used by the Archer class, as the Archer's own version of Necron's Blade, the Scylla, is highly inferior to the Valkyrie, unless they want to optimise their Crit Chance and Damage.

Comparison: Valkyrie vs Hyperion
The only two real contenders for the best sword in the game are the Valkyrie, for Berserkers and the greatest amount of melee damage in the game, and the Hyperion, for Mages and the greatest amount of magic damage in the game. The Valkyrie is often used in conjunction with the Berserker branch of the Wither Armour, Necron's Armour and the Hyperion with the Mage branch of Wither Armour, Storm's Armour, increasing Strength and Crit Damage and Intelligence respectively. Whilst the Valkyrie is often used with Soul Eater, as its lack of Intelligence makes the scrolls useless and unspammable, and Soul Eater is the best enchantment for melee damage, the Hyperion's high intelligence means this is often used with the Wither Impact scroll, and the Ultimate Wise enchantment. Both of these swords are described as seriously overpowered, but from an unbiased point of view, the Valkyrie is better at Mini-Bosses and Bosses, and can mow through tanky mobs with ease, whilst the Hyperion, using the Wither Impact scroll, is better than the Valkyrie at mobs of enemies. However, the fact that Mages and especially the Hyperion becomes useless when all mana is expended, the Valkyrie becomes superior. Also, the fact that the Hyperion relies heavily on a high intelligence stat means that it cannot be used properly with Necron's Armour, which regardless of the class is the most powerful armour set in the game is a heavy downside. There is also the fact that the Valkyrie setup is more cheap. The only two major flaws with this sword is the lack of efficiency even when the Wither Impact Scroll is applied for clearing rooms and the fact that this cannot be used as a ranged weapon. This problem can be solved using a Flower of Truth as a ranged weapon, and for room-clearing, a bow like the Explosive Bow, Machine Gun Bow, or even a cheap magic weapon with Ultimate Wise on it such as the Spirit Sceptre is recommended.

Warning: The below technique is highly risky and may result in hundreds of millions of coins lost.
The main problem with the Hyperion is that while its AoE is great, it doesn't actually deal that much damage, and while the Valkyrie deals massive amounts of damage, it struggles against crowds of enemies. As you can see, one is weak where the other is strong. So what would happen if we used it together? Against tanky Mini-Bosses and Bosses, use the Valkyrie with Necron's Armour to blitz through them, and against mobs of... well, mobs, use the AoE of the Wither Scrolls with the Storm's Armour to constantly spam the scrolls. Doing this may be highly inefficient and result in a billion coins lost, so be cautious.

Obtaining
It costs 8 Diamante's Handles surrounding a Necron's Blade.