If you are vs a high CC team go beads instead of aegis, also if you find you run out of mana too fast replace a heal pot wit a mana pot.
if you play against a high movement speed team and are ahead consider swapping an item of your choice (anything except rod of tahuti) with Typhons. Its talked about as a meme but the Typhon beast has insane movement speed and will run down junglers and carries as long as you "chase" behind the typhons beast.
you dont have to replace this necessarily follow above description
