Build 1: ADC Fighter

Face to face close combat. Purchase sequence:

1. Berserker's Greaves. Increase your walking and attack speed.
2. Bloodthirster. It regen your health while attack. 70-100 attack damage. Good in early game combat.
3. Phantom Dancer. Greatly increase attack speed and critical strike.
4. Infinity Edge. Greatly increase attack damage and critical strike damages by 50%.
5. Another Phantom Dancer. Total attack speed is increased to 120%. Activate Highlander, total attack speed is increased by 200%. Critical strike chances is increased to 85%.
6. Frozen Mallet. Slow down your enemies, prevent them to escape. Increase Yi's HP. Add some more damages.


Build 2: Back Door Master Yi

1. Mobility Boots. Run fast. Reach target turret faster.
2. Bloodthirster. It regen your health while attack. 70-100 attack damage. Good in early game combat.
3. Phantom Dancer. Greatly increase attack speed and critical strike.
4. Infinity Edge. Greatly increase attack damage and critical strike damages by 50%.
5. sight ward. Put at main path in the jungle. Prevent gang efficiently. At least 3 sight ward must be placed for invading a turret.
6. Oracle's Elixir. Detect any enemy's sight ward and Teemo's mushroom. Prevent your location to be revealed.

Ghost
Walk fast. Chase and attack enemy, escape from enemy.

Teleport
Enable Yi to perform Back Door Attack more easily.

1. Teleport to a minion closest to enemy's turret.

Notice the map, when a group of minions has reached and attacking a turret, teleport to one of the minions that is being attack by turret. Yi should be able to destroy a turret easily.


2. Destroy a turret alone without minions.

Walk to a turret. Place a sight ward near the turret.
Attack the turret. Yi will be attacked by turret.
Quickly damage the turret as much as possible.
When Yi's HP is low, quickly retreat back to base and heal.
The turret's HP should be 50% left.
Then, use Teleport, teleport Yi to the sight ward and destroy the turret.


3. Attack turret with an ally champ.

Request help from an ally champ to assist you to receive a few attacks from turret.
Any champ, tank or non-tank.
The few attacks received by your ally champ will buy enough time for Yi to destroy a turret.