AP yi is also great at Harassing. How many champs can harass like that in safety? Wait for there to be only like 2 minions and boomerang off them and hit the champs but land back at the minion location and retreat. Repeat and you dominate the lane. He can also stay in lane really well with meditate. It is also a great defense for being tower dove. Alpha so you cant be targeted and hit them then meditate for super armor and healing while they are in your tower.
