Run in after the tank/tanky, Ultimate immediately, disable the most threatening with Three Talon, you are a XinRar.

When farming, keep in mind of his passive, it literally feeds you your health; so don't shy away from harassment. Remember to last hit the creeps, mage creeps are nearly two hits without damage.

You can have this exhaust/ghost combo, since I see it as best or sub in ghost for flash, either way Xin must be careful as he is likely to be put down swiftly.

Banshees for Magic Resist.
Force of Nature for Magic Resist.
Thornmail for massive AD.
Last Whisper for tanks with armor.
Madred's Bloodrazors for High Health.

Passive - Tireless Warrior -
Q - Three Talon Strike - Signiture. Use it on the poor sucker that's not getting away this time.
W - Battle Cry - Used to regain health a bit faster via passive or obtained lifesteal.
E - Audacious Charge - A Small AOE teleport/slow and a catch-up/creep-escape ability.
R - Crescent Sweep - Percentage of health/AD , and very very very good via teamfights.

Occasionally hit creeps for passive health refresh.
I like to hit creeps twice with three talon, and charge/talon an enemy.
Use Battle Cry to refresh Crescent Sweep.
Charge is a small AOE slow, use creeps! Or save your *** with it- rarely.
Crescent Sweep is a threatening team fight ability.

Pros
- Disables
- Can be tanky
- Gets fed
Cons
- Terrible escape maneuvers
- Targeted
- Slight trouble with tanky harassers

1v1 determined.
Very important support/damage.
Can be squishy.
Be a "freelance".