Xin zhao is a tanky dps so he need to be tanky and have a good amount of dmg.

My build :

Start with Doran's Shield. Go solo lane or bot lane with a support. Just last hit with Three Talon Strike and get a kill if you feel you can.

Go back and get a Heart of Gold with Berserker's greaves. Now you are suppose to be 6 and you should dominate your lane. Get a lot of last hit and if dont be afraid to go in team fight first. Never back fight until the end!! You never know what will happen with Xin Zhao.

Next get Catalist and upgrade it into Banshee's veil. Get a Atma's impaler its good for the dmg and armor. Get the black cleaver for attack speed and dmg. After you can buy randuin'S omen and finally get Bloodthirster.

You will destroy the ennemy carry with the red buff and you have enough amount of armor and MR to stand against nukers!

Have fun with my build ill try to improve it. I did it in 5 minutes but this is a very good build!!