Weapon evolves by earning points. Any match won using Phantom Assassin will earn you 1 point. Earning 40 points will upgrade the weapon to Level 2, and earning 100 points causes the weapon to reach its maximum evolution.
Hero
Phantom Assassin
Slot
Weapon
Rarity
Arcana

Exalted Feast of Abscession
Masque of Awaleb
Crux of Perplex
Shoulders of the Bladeform Aesthete
Announcer: GLaDOS
Infernal Chieftain
Atrocities of the Abyssal Scourge
Fractal Horns of Inner Abysm 