Zilean is a character who has a wide range but is easily harassed. Zilean mostly ticks people off from his barrage of bombs and his ultimate which allows him to revive. Zileans passive is to revive himself or an allied champion which is great when saving a key player whom is vital in the game

the runes are balanced out to give you experiance and penetration so buying pen. items are less of a hassle and if you dont have the money you dont need to woorry about it. Zilean needs to get to llevel six as fast as possible which is why we use runes for experiance bonuses