Xin Zhao is one of my mains because of the fact that he can run in quickly do a ton of damage and get out with out having to worry about just about anything. Xin Zhao is in my opinion a power house and this is how i make him that way.

Xin Zhao, being a power house in this build, i chose to take straight AD runes to make his early game AD very high, now all my runes are AD except for the seals. i chose to make Xin start with 9 seals of malice, starting his game off with crit chance to make him that much more of a threat to all the people he is laneing against.

For masteries i chose to go 21 9 0 to focus on AD mostly but keep a little bit of armor and magic resist to keep Xin trucking like the champ he is.

Now for Xin like i said i will focus on AD and crit chance so Xin will hit very high, now for my items i start with my dorans blade for the extra bit of harassment at the start, i follow that up with berserkers then a phantom dancer so work on attack speed and crit chance. i go from that straight to my bloodthirster for the attack damage and life steal for sustain. after that i go for infinity edge for the crit chance and damage but also the attack damage. after my infinity edge i work on getting warmogs because by now Xin already is hitting really fast and hard and with all that HP no one will be able to kill you. i follow that up with your choice of a bloodthirster for sustain or a phantom dancer for attack speed.

Xin has an unconventional Skill sequence because i don't focus on getting any skill maxed quick, i move my ability points around a lot because Xin need certain abilities at certain times and i find that this sequence if perfect for being the Power house that Xin is.

Xin having no way to escape a gank i chose flash to help me survive those uncomfortable moments or fights that don't go your way. now if you prefer ghost that is a great option also. for my second spell i chose ignite so no one will get away with half a bar of health again!