High mobility for gank effectiveness and sticking to target.
Empowered abilities and resource manipulation
Hitting an enemy champion with 3 attacks or separate abilities grants a burst of MS.
Gain a magic damage shield when taken to low health by magic damage.
Gain 3% extra MS. Gain extra AP or AD, based on your bonus MS, Adaptive.
Gain MS and AP or AD, Adaptive when in the river.
9% attack speed, 10 ability power or 6 attack damage
Takedowns restore health and grant bonus gold.
Takedowns on enemies grant permanent Attack Speed.
Phase Rush on Xin Zhao allows you to engage a gank with your [E] and easily stick to your target for repeated damage and [Q] knock-up.
Nullifying Orb allows you to make aggressive early ganks mid and bottom as well as take jungle skirmishes against AP junglers like Elise/Sejuani/Zac.
Celerity's bonus Movement Speed synergizes well with Phase Rush and Waterwalk giving you massive mobility and ability to stick to gank targets.
Waterwalking allows you traverse the jungle incredibly quickly and skirmish for neutral objectives with a lot more power and mobility.
Triumph's massive mid-fight heal is fantastic for allowing you to jump and kill a backline target while still being able to stay in the fight without an escape.
The extra bit of Attack Speed on Xin Zhao means a faster jungle clear and burst damage in fights for a quicker [Q] knock up proc.
Patch 8.10 saw a buff to Phase Rush and jungle duels for scuttle making Xin a powerhouse.