T1. Seasoned Marksman:
Increases basic attack damage by 1 for every 6 minions killed (heroes count as 3). Stacks are halved upon death. If successful you should end up with around around 25-35 stacks at the end of the game.

T2. Vampiric Strike:
Heals for 25% of damage dealt. This helps mitigate your incredibly low HP and defense.
**If you are doing really well and don't think you need the healing, you can opt for Searing Strikes. This is an activated ability that increases your basic attack damage by 50% for 5 seconds, and costs 15 mana per hit while active. This will help your sustained damage and when combined with Shadow Assault can be horrifying.

T3. Void Slash:
Increases Cleave damage by 30% if cloaked. This helps you gank unexpecting victims by increasing your burst damage which is what this build is all about.

T4. Shadow Assault:
I go over this in abilities section. The alternative, Void Prison, instantly puts everyone in a radius in a stasis which can be very powerful when combined with other hero abilities but it requires a lot of coordination which you don't find in most PUGs.

T5. Giant Killer:
This is where things start getting fun. Your basic attacks now deal bonus damage to heroes equal to 1.5% of their total health. Tanks are now gankable.

T6. Double Bombs:
After using Singularity Strike, this allows a second singularity strike to be cast for free at 50% damage for 3 seconds. This is good because you get an extra 3 second slow upping the slow time to 6 seconds if used perfectly. The extra burst damage helps as well. Sometimes i put 2 sing. strikes on back to back if i know it will kill the target.

T7. Void Blades:
This is an epic talent. Increases your basic attack damage by 20% AND your basic attacks now slow targets for 1 second. Any chance of an opponent getting away is now gone. By this time you are hitting EXTREMELY hard with BASIC ATTACKS (no cost)!

Cleave:
This is a small radial AOE that deals high damage for low mana cost. You should be using this often. It is a good minion wave clearing ability. It can be used as a quick hit against a hero. It can also be used to deal high dmg when enemy heroes are grouped up tightly. At 40 mana cost and 6 sec cooldown it is your most versatile ability.

Singularity Strike:
This is a projectile that takes some practice to use. It will attach to the first enemy it hits and after 1 second, explodes dealing even more dmg than cleave, and slows by 40% for 3 seconds. The key with this is to have a clear path to your target to ensure it hits them. It is moderately expensive to use at 60 mana and a 12 second cooldown. If you miss it is a big waste of mana and most likely results in a failed kill attempt. Master this and zeratul doubles in deadliness.

Blink:
This ability is what makes zeratul such a strong ganker. It instantly teleports zeratul anywhere in a large radius. You can blink past structures such as walls, gates, and bushes that are normally impassable. It is expensive at 75 mana but will save your *** or give you a kill. Use it to escape from danger or chase a guaranteed kill. This will be your favorite button.

Shadow Assault:
Your Heroic Ability. This is not as good as characters heroic abilities but its okay, we aren't relying on it. Activate it to increase your attack speed by 20% and charge during basic attacks for 6 seconds. It costs 100 mana. I use it when fighting a tank or high health character. Also use it to chase a valuable kill that is getting away from you.

Permanent Cloak:
This is your passive trait. It is what makes zeratul the assassin he is. When cloaked, he cannot be targeted by enemies or towers (aoe can still hit him). He is invisible on the minimap. On the battlefield he is 99% transparent which means a trained eye can still see where he is, but cannot target him. He becomes decloaked when using abilities/basic attacks, using hearthstone, mounting up, or taking damage. You want to stay cloaked as much as possible. Cloak lets you safely stand near enemy towers, and bypass enemy minions without getting attacked so early game use this to gain visibility of the map.

Standard "Rotation":
There is not definite order to these abilities but this is how most kill attempts will go.
1. Be cloaked and on mount
2. Approach target
3. Cleave/Singularity Strike
4. Basic attacks
5. Either blink out and wait for cloak OR blink in to secure kill. If they are getting away with low hp Shadow Assault to secure kill.

Early game (5-10 mins) should be spent assisting other lanes in securing kills. You have to be patient and wait for the prime moment to decloak and strike. You need to rely on your cloak to stay out of danger and ensure you are only decloaked to go for a kill, or to kill minions when no enemy heroes are present. Attacking at the wrong time will almost always result in a death. Zeratul is extremely squishy and WILL DIE EASILY if you are not careful. Never attack near enemy towers unless you know you can get the kill and blink out. This build relies on a strong early game by assisting teammates in finishing their opponents. You need to be building stacks of seasoned marksman by getting kills and helping clear minions.

By midgame (10-15 mins) you should START to be more comfortable being uncloaked. This confidence will come from Vampiric Strike which grants health on basic strikes. If you ever find yourself low but don't want to retreat, find a pack of minions to attack (don't be afraid to "waste" a cleave on minions). Also, provided you are getting kills and killing minions, you should be dealing heavy damage with basic attacks thanks to Seasoned Marksman. If you are playing successfully you should have 15-20 stacks by midgame. You should also have your Heroic ability by now. I use Shadow Assault to secure a kill that I thought I had but is getting away from me. It closes gaps and increases attack speed so it's a great way to turn things around and surprise opponents. You should still be playing carefully and mainly assisting your teammates in finishing off enemies who would have gotten away. The best kills are done by finding an opponent who's chasing a low health ally and launching a surprise attack.

By late game you should be dominating. The last 3 talents you pick up ensure that you are the hardest hitting player in the game. You're opponents will know that they are not safe anywhere on the map. As soon as you show up you will see them run. You can probably take on most 1v1 but still the best way to play is with the assistance of your allies. Even if they are bad, just having them as a distraction will be super helpful. Dont get too cocky because you are still extremely squishy.