The Black Blade of Chaos is a unique two-handed sword (Odachi) introduced in Last Epoch, notable for its synergy with the Rogue’s Bladedancer mastery and its impact on the skill Lethal Mirage. Forged with shadow iron under an unlit moon to harness Lagon's elemental chaos power, it requires level 72 to wield and serves as a premier weapon base with a high melee critical strike multiplier Last Epoch Gold.

What sets the Black Blade of Chaos apart is how it fundamentally changes Lethal Mirage, a core Bladedancer skill. Normally, Lethal Mirage grants a brief invulnerability window with a long cooldown, used as a powerful burst attack every 10 seconds or so. However, when wielding this blade, Lethal Mirage no longer grants invulnerability but instead becomes a much faster, more frequent attack, drastically altering playstyle from a cooldown-based nuke to a rapid, evasive melee assault.

This unique mechanic has inspired several distinct build archetypes centered around the Black Blade of Chaos:
1. All-in Shadow Daggers Build: Focuses on maximizing damage from Shadow Daggers, leveraging the blade’s synergy with Dexterity and flat damage bonuses. This build emphasizes evasion and quick attacks rather than heavy melee strikes.
2. Bleed Build: Attempts to capitalize on bleed effects, though the weapon itself lacks explicit bleed-related stats, making it less optimal without additional support.
3. Lightning Damage Build: Uses Dexterity scaling and lightning penetration to boost damage output, combined with cooldown recovery to maintain rapid attacks.
4. Shift Crit + Shadow Daggers Hybrid: Balances evasive play with critical strikes and Shadow Daggers damage, creating a fast-paced, high-mobility combat style.

The weapon provides Dexterity bonuses and lightning penetration, and its synergy encourages investment in cooldown recovery speed, dodge rating, and movement speed to maximize survivability and damage output.

Despite its innovative mechanics and thematic appeal, the Black Blade of Chaos has some downsides. It lacks explicit damage-boosting text on the weapon itself, meaning it relies heavily on gear and passive tree synergies to scale damage effectively. Players often need to carefully balance cooldown reduction and survivability stats to optimize its potential buy Last Epoch Gold.

In summary, the Black Blade of Chaos is a unique Odachi that transforms the Bladedancer’s Lethal Mirage skill into a fast, nimble attack, enabling new Rogue playstyles focused on speed, evasion, and rapid strikes. While not necessarily the highest damage option, it offers a fresh and engaging combat experience for Last Epoch players seeking a ninja-like melee build.