The recommended build for Yi Sun-shin focuses on maximizing his physical damage output, critical strike potential, and sustain, complementing his Assassin role.
First, Endless Battle is a core item. Its Unique Passive - Divine Justice, which makes the next Basic Attack after casting a skill deal 60% Physical Attack as extra True Damage, synergizes perfectly with Yi Sun-shin's kit. His frequent skill usage, especially Traceless and Blood Floods, allows him to consistently proc this passive, significantly boosting his burst damage and overall sustained damage through True Damage.
Next, Flame Hunter's Magic Boots provide essential movement speed and jungle clearing capabilities. While the boots offer movement, their Unique Passive - Hunter is crucial for jungling, dealing 25 + True Damage to creeps over 3s, with damage increased by 100% for non-Marksmen heroes. This helps Yi Sun-shin clear jungle camps efficiently, allowing him to gain gold and experience quickly to scale into the mid and late game.
Blade of Despair is a high-damage item that further amplifies Yi Sun-shin's killing potential. Its Unique Passive - Despair increases Physical Attack by 25% for 2s when dealing damage to non-Minion enemies below 50% HP. This passive activates before the damage is dealt, meaning it helps Yi Sun-shin execute low-health targets more effectively, turning trades into kills and securing objectives.
Berserker's Fury is vital for enhancing Yi Sun-shin's critical strike damage, which is already boosted by his Heavenly Vow passive. Its Unique Passive - Doom grants 5% extra Physical Attack for 2s upon critical strikes. This item significantly increases his burst potential, especially when combined with his enhanced basic attacks, allowing him to shred through enemy health bars rapidly.
Malefic Roar addresses the issue of enemy armor stacking. Its Unique Passive - Armor Buster grants 0.125% extra Physical Penetration for each point of the enemy's Physical Defense, capped at 40%. This ensures that Yi Sun-shin's damage remains effective even against tankier opponents who build defensive items, preventing his damage from being mitigated too heavily in the later stages of the game.
Finally, Immortality provides a crucial layer of survivability. Its Unique Passive - Immortal allows Yi Sun-shin to revive 2.5s after death, gaining 16% Max HP and a 220-1200 shield (scaling with level) that lasts 3s. Given Yi Sun-shin's low durability score of 40, this item offers a second chance in critical teamfights, allowing him to re-engage or escape after being focused, making him less susceptible to being instantly shut down.