Pros:
Very tanky with high damage
Can become a one man army
Benefits off Tier 2 items
Great farmer
Has amazing lane dominance
One of the best 1v1
Cons:
Squishy early on

Other than that no other cons.

This is my Xin Zhao guide. As far as it goes i used to be an extremely good Xin and would almost always win when playing him.

So the runes are pretty simple. Xin Zhao has high base damage on his abilities and really only needs 2 ad items and maybe an as item. With that that's why I take the armor yellows and mr per level blues. The armor pen just helps him out a lot.

Masteries are self explanatory too. Like stated above he doesn't needs to much damage so i go 21 in defense to help me out and the 9 in utility is just great as well.

For items I start with Cloth armor and 5 health pots and then rush 2 HoG. I get tier one boots there and now you have to make a choice. Are you laning against someone with a bit of armor? If yes get brutalizer if no get wriggles. I get my merc treads there and then get the other one.
If you want to do more damage get a zeal if no then start building a Banshees

Xin Zhao has a nice gap closer and I use that to focus down the enemy carry. He is very tanky and can usually be in the fight and survive. Make sure your team knows your going in though or your probably going to die.

That's my guide and remember to rate it please.