There are a couple combos that all have their own merits however the following combo is easily the most consisent and flexible allowing you to engage from far away, immediately stunning and guaranteeing you actually get your damage off. This combo requires Aghanim's Scepter and starts with the Kazurai Katana equipped.

1. (D) Switch Discipline

2. (R) Raven's Veil

3. (D) Switch Discipline

4. (W) Grappling Claw

5. (D) Switch Discipline

6. (Q) Falcon Rush

7. (D) Switch Discipline

8. (Q) Echo Slash

Practice this combo until you can do it without thinking.

There are combos that don't require Aghanim's Scepter but they are a lot less effective and this build focuses on the late game scaling way to play Kez, which in my opinion, is the best way to play him.

Not really a combo but something to practice is abusing the hidden value of the Shadowhawk Facet. Holding Alt while hovering over the Facet reveals reason we pick it.

It states "When Kez triggers a Shodo Sai Mark, reduce the cooldown of Shodo Sai."

This means, when parrying an attack and subsequently hitting the marked target the cooldown of Shodo Sai will almost be reset allowing you to immediately parry again and restart the cycle. This goes through debuff immunity.

This can be a little awkward to do because it is easy to accidentally cancel the parry with auto attacks but if you listen for the sound that a successful parry makes to start attacking it becomes a lot easier.

General Tips For Each Ability:

Echo Slash - This is your prefered Q in the laning stage as long as you can consistently get both slashes to hit. Use this on parry marked targets to make sure they both hit.

Grappling Claw - You can cancel your attack animation with this by immediately using it after attacking making it very good for last hits, trading in lane and getting extra attacks in Falcon Rush.

Kazurai Katana - Makes your trading in lane deceivingly strong due to the percentage DOT. Punish tanky offlaners who think they can bully you. With Falcon Rush these stacks can add up quickly.

Raptor Dance - This can be very effective for turnarounds or executions however, it has been nerfed really hard so, only use it if you are confident it wont get canceled.

Switch Discipline - If you took the Flutter facet, spam this when moving between camps or lanes for the speed boost and bonus damage, but make sure you end up in the prefered Discipline. In lane, you want to stay in the Shodo Sai Discipline as much as possible so that you can parry and subsequently Switch Discipline if an enemy attacks, however the Kazurai Katana Discipline has higher range and more damage and might be needed to get last hits.

Falcon Rush - Combine this with the Kazurai Katana Discipline for damage or stay in the Shodo Sai Discipline for CC.

Talon Toss - This has a lot of utility. Getting last hits from range, canceling channeled abilities, stunning marked enemies and silencing slippery heroes.

Shodo Sai - Dont forget to use this, especially against ranged heroes. Combined with Echo Slash, you can do a lot of burst damage in lane. Remember, with the Shadowhawk facet, hitting a marked unit basically refreshes the cooldown when it's at level 4.

Raven's Veil - This is your initiation ability. It removes the vision of the enemy making them disoriented and an easy target. It can also be used defensively as it gives MS, dispels and makes you invisible.