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

Radiant Conqueror Shoulder
Dragon of the Outland Ravager
Inscribed Black Pool Watcher
Obelisk of Foresight
Butter Blunder
Exalted Feast of Abscession 