(Highly Recommended For versing people like Ahri, Zyra, Kat) OR
(note: wait 10 seconds after minions spawn) (Recommened For Versing TF, Ryze, LB)
First Back Goal: 1,000 Gold(with tome)
early if countered by talon, panth, etc.
Second Back Goal:
Mid Game Goals(Your Build By Now)
Those four items are almost always built. Morellonomicon is not always seen built on AP carries nowadays, however, the CDR is a must have, the mana regen in lane helps insanely, and you get a good amount of AP from this item. Also, its a great counter when versing someone with an HP regen such as Yorick, or Mundo because of the healing reduction.
Late Game Item Possibilities:
WoTA: Great Item, provides spell vamp, however i recommend building a more offensive item, with another defensive item to finish your build
DFG: Great item when versing a malphite, shen, rammus, anybody tanky really.
Abyssal Scepter: Always a great choice, if their APC bursts hard, this is a definite want. With your zhondas and ult youre extremely tanky.
Frozen Fist: If they decide to go AP-less and have talon mid or just have heavy AD, this is a great item. Provides you CDR, Armor, AP, Mana, and the Sheen Passive which works well with your E ability.
Ryali's: Probably the safest choice of an item. Easy baits, never ending slows, lots of health. Great item to take into consideration.
Void Staff: Because you can never have enough Magic Pen. However, i personally don't build this item, but I have seen other people build this item and do well, so it's whatever you're comfortable with.
Warmog's: Why did I throw this item in? This item is rediculously good because it provides a ton of HP, and lots of HP regen. If you're going to get out of sticky situation's, you're going to need this. During team fights, once you land your Ultimate, your health will be off the charts.