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

Blossom of the Merry Wanderer
Sea Rake's Bridle
Fiery Soul of the Slayer
Blade of Tears
Severing Crest
Auspicious Cluckles the Brave
Inscribed Crystal Dryad
Autograph Rune
Golden Staff of Gun-Yu
Loading Screen of the Chainbreaker
ESL One Jagged Vision Ward
Exalted Bladeform Legacy
The Hierophant's Protection Set
Darkclaw Emissary Cowl
Fractal Horns of Inner Abysm
Chaos Fulcrum
Resentment of the Banished Princess
Tory the Sky Guardian
Belt of Eternal Night
Artificer's Chisel
Radiant Conqueror Back
Lamb to the Slaughter 