For you xin to have amazing attack speed, but there are fears of you teammates stealing your kills, but you play supportive, you could set up team kills.

Using the exhaust ability will help getting kills early game if you play defensive. Using exhaust skill near you turret along with your combo skill could do great in getting a kill. Exhaust is also good for chasing those runaway foes (along with frozen mallet)

Remember this build is what I created for players who aren't greedy when it terms for kills, like chasing down an enemy with low life by yourself, even though there are enemy champions near by and then they manage to kill you without you reaching your prey. Some of you should learn that no death is worth a kill. You are feeding you Enemies....

One Xin's weakness is having no escape mechanism, well that could be counter acted by using flash at the right time. Using Flash and Xin's speed you could easily escape backstabbing enemy ambushes. Only if you know how to use Flash well.

In playing defensive, You should able to anticipate your opponents moves like when there is a champion that could become invisible, do ward play or the use of Oracle, your opponents ambush setups might backfire on them. like Shaco placing alot of boxes Behind the bushes. using ward would warn you not to chase him and avoid death. Using Oracle can be good for clashes when you aren't inside the clash, you can spot invisible enemies approaching to take advantage oflow life champions after the clash. like Twitch incoming from behind, sometimes you could catch him scouting around your team-mates, saying close to you team allows your team to rush him without him being able to fight back.This works great with Evelyn as well, making her stun attack lose timing. or making it virtually unsusable

This has been my firt build out of experience...PEACE