Watch out for Xin’s level 2. His and provide him both with an attack speed buff, a gapcloser, an auto attack reset and a knockup.
After level 6, Xin’s renders him invulnerable from all damage sources outside of its range. Don’t count on DoT (damage over time) effects to finish him off if his is active.
Xin has no real disengage in his kit apart from his ; and only one way in- not out. This coupled with him building multiple damage items means that he is vulnerable to multiple melee characters in a teamfight.
Xin is vulnerable to CC during teamfights, don’t ignore him. Focus him down when he engages.
Xin is a strong duelist given his engage, sustain damage and CC, but he struggles dealing with multiple champions with his down. Tanks with CC are great at locking him down.
Xin is very immobile on his way out of a fight, punish him for going too deep. Same goes for picks, if Xin is out of position, he is easily chased down.
Xin is very strong early in the game, his level 2 ganks are very powerful.
Once Xin gets Trinity Force and the Warrior Enchantment, this is typically the most damage he’s going to have in a given game.
Xin falls off once he is unable to one shot anybody. The later the game goes, he is going to find it harder to survive team fights and assassinate anyone.