This is how i play Zed in season 3 and i've gotten very fed almost every game i play with him, he is my main and favourite champion and he is super funny to play. As i said in the notes of the items i buy the items in different orders depending on the enemy team for exmaple if the ad carry is very fed i buy randuin's omen pretty fast but if the ap carry is fed then i buy maw of malmortius earlier in the game. The boots also depend on the enemy team, if you're doing super good you could buy Boots of lucidity (cooldown reduction) but in most cases i prefer Mercury's treads. The bloodthirster in the end i only buy if i'm fed otherwise i usually buy items like Guardian angel or Frozen Mallet. Hope this is helpful! :)