• Attack Animation: 0.4 / 0.7
• Damage: 44 - 50
• Casting Animation: 0
• Armor: 1.9
• Base Attack Time: 1.7
• Movespeed: 280
• Missile Speed: 900
• Attack Range: 600
• Sight Range: 1800 / 800

There are some things that are interesting here. He has a fairly nice attack range, he's slow (but Wex can fix that), etc. But the really crazy thing is his casting animation. Zero.
This means that you can cast many spells instantly by shift-queuing (example: Hold Shift and [move to location, cast wex, cast wex, cast wex, cast tornado, cast invoke] and then cast emp). It also means that, if you do it right, the enemy might not know that you cast a spell like sunstrike at all. Note that many of Kael's spells have some built-in delay to prevent the no-casting-time thing from being too good (meteor, emp, sunstrike), but that the others, for example cold snap, can be used while chasing without slowing down (if you shift-queue well).

Quas
Quas grants .75 HP regen for each level of Wex. This is granted once per active Quas reagent (you can have 3 reagents active).

Quas is the most passive reagent you can activate. It gives little benefit in clashes, but can be useful between them to heal up. 3 instances of level 3 Quas provide roughly the same rate of healing as a tango.

Wex
Wex grants 2% IAS and 1% ms for each level of Wex. This is granted once per active Wex reagent (you can have 3 reagents active).

Wex is a powerful reagent to have active. It increases your DPS by a bit due to increased IAS. More importantly, it increases your mobility a great deal. Turn this on to get places or when you sense an incoming gank - movespeed can save you from many situations.

Exort
Exort grants 3 damage for each level of Exort. This is granted once per active Exort reagent (you can have 3 reagents active).

Exort is a very strong reagent during the laning phase. The increased damage makes last-hitting much easier and harassing more effective. It can be used to increase your DPS through much of the game.

Invoke
This is the spell that makes your other spells. Level 2 (available at level 7) is needed to give you access to 2 spells at the same time. The other levels give you the ability to cycle through more spells at the cost of a greater mana cost to invoke - this can be solved completely with Aghanim's which greatly reduced the cd of invoke and makes the mana cost 0. This is why Aghanim's is a part of any serious Invoker build.

Cold Snap
An interesting disable. Basically, whenever damage is dealt to a target that was cold-snapped, they get ministunned (.4 sec) and damaged (30 damage). Increasing Quas reduces the minimum amount of time between stuns (from .77 to .6) and increases the duration of cold snap (from 3 to 6). Due to the way it works, Cold Snap is great with heroes that do DoT to maximize the number of stuns (eg, Ion Shell). It has a fairly low CD (20s) and an amazing cast range (1000).

Ghost Walk
This is mainly used as an escape mechanism, but it also has a significantly useful slow; note that enemies will be able to tell you're there due to the slow so it's not useful for anything stealthy. The spell slows you (from 30% to 0% [W]) and the enemies (from 10% to 40% [Q]). It affects 400 AoE around you.

Tornado
This is a fairly basic nuke with an additional cyclone effect. It can get up to 3100 range [W], and cyclone for up to 2.2s [Q]. It has a low 25s CD and affects an AoE of 200. Note that its casting range is 2000, so you can hit enemies much farther out by clicking partway to them.

Tornado's range is unbelievable and can be used to snipe running enemies. It can farm creep waves extremely fast (in a Q/W build, it can often kill the range creeps outright). The disable time is helpful to gain position for you or your allies (both by fleeing or catching up).

This spell can be used to cancel channeling spells, as primary initiation from afar, to save people, to make sure enemies die and to push/farm. It has a fairly short cooldown making it a reasonable spamming spell.

EMP
This skill is insanely powerful against strength casters. It can remove up to 400 mana and half as much hp [W]. Note that since EMP is direct removal, it will work even if the enemy is cycloned (like by Tornado). It is a little hard to land due to the delay between cast time and the effect (4-2 seconds [W]) and the small cast range (400). However, the large AoE (700) and Tornado or allied stuns can make it one of the most powerful tools at Kael's disposal.

Alacrity
Alacrity is an underused buff for dpsers. It gives from 30-90 IAS [W] and 20-80 damage [E]. Due to the duration and cd, you can keep this on a carry for nearly half the time. The IAS can be crazy powerful on heroes like Sven, Magnus or Tiny. The damage can allow a carry to focus more on survival items and less on damage (like a BKB on DK or PA).

Chaos Meteor
The aptly named Chaos Meteor is best used for creating chaos in a battle. It is also Kael's most potentially damaging spell. It does large amount of damage at the meteor itself (300 AoE) and much less damage for 3 more seconds. The distance it rolls goes from 465-1410 range [W]. The damage at the meteor varies from 80-260 dps [E] and from 8-26 dps [E] for 3 seconds afterward. Due to the fact that the damage is much higher while the enemy is in the AoE of the meteor, it is often used in conjunction with Deafening Blast to push the enemy along with the meteor.

Sun Strike
A simple nuke except for the delay and global range. You can cast it anywhere and it will split its damage among the enemies in the 200 AoE. It does from 74-450 damage [E] and has a 1.7 second delay before the cast goes off.

In order to aim it better, you can take an enemies ms into account and aim ahead by that amount times two (this will be roughly 600 or 700 units ahead most of the time). The AoE will help make up for some misjudgment.

Forge Spirit
AKA Invoker's ranged infernals, these spirits can be very painful for enemies and do a great job at razing buildings. Quas increases their duration (20s-80s; note that you can only have one group alive at any time), armor (2-8) and mana (100-400; used for their armor-reducing orb). Exort increases their HP (300-900), damage (29-83) and range (300-900). Note that any build that wants to use forge spirits should level both Q and E to 4: when this is achieved, this spell will summon 2 spirits instead of 1.

Ice Wall
This spell is deceptively powerful. Its slow (20-80%) is intense enough with Quas leveled that it will slow enemies to minimum ms. It is worth noting that the slow goes through BKB. The damage [E], ranges from 6-42 dps. Usually Wall is put up for the insane slow, but radiance-like dps isn't to be scoffed at either. After 4 or so levels of Quas, the enemies are slowed to a crawl, but more levels of Quas are powerful in order to extend the duration of the wall (3-12s). It's often a better escape skill than Ghost Walk, especially when the enemy has AoE or has cared enough to get dusts.

Deafening Blast
This spell is amazing. Once you are fully leveled it does 280 damage [E], has 1.75s of full disable (during knockback [Q]) and silences attacks for 4 seconds after that [W]. The damage is ok, but the crazy portion is the duration of the disable. It has a 40s cd, and affects 250 AoE. It's cast range of 1000 lets you sweep out a long rectangle of disable.

This spell can be used to cancel channeling spells, as secondary initiation, to save people, to make sure enemies die and, later, to push faster. It's mostly saved for team battles or used as a secondary disable to save yourself/allies or ensure an enemy's death.

Level 01 - Exort
Level 02 - Quas
Level 03 - Wex
Level 04 - Invoke (invoke Tornado)
Level 05 - Wex
Level 06 - Wex
Level 07 - Invoke (invoke Deafening Blast)
Max Wex
Max Quas
Max Exort
Get Invoke as possible/desired

I generally keep invoke at level 2 for quite a long time since this build doesn't cycle through spells much. If you'd like, feel free to get another level earlier than I do (for Ghostwalk, EMP or Icewall). If you're just learning how to leverage Invoke, I suggest using this build to learn and comboing Tornado, EMP and Deafening Blast.


Core Items:

The first few items are there to help with your paper HP. Eul's grants you an ms boost and an additional disable. It can also handle your mana needs quite well. BoT gives you the mobility you need to start being your team's knight in shining armor. With 484 ms and teleportation, you can be where you need to be to gank, push, countergank, teamfight and just outright save allies who were in the wrong place. Next we get Yasha to permanently move at max ms - great fun.

Extension Items:
Guinsoo's provides one more disable (one of the best in the game) and infinite mana. Also some marginal survivability and dps (due to Wex and Yasha's IAS).
Manta might seem odd, but it's fairly effective (also cheap since you have Yasha). The idea is to go to a lane, push it quickly with your spells, spawn images (and spirits later on) and move on. The images give you a way to deal minor damage to buildings (if you can push that far) or push a little farther at very little risk to yourself. This kind of pushing puts a lot of pressure on the enemy.



Your job with this build is to set the pace of the game. You decide when fights will occur. You make pushes happen and break them. You set up ganks and counter them. Control is the name of the game and, with 9 seconds of AoE disable, max ms, teleportation, and a single target disable, you are its master.

Early game will not be easy, but once you get to mid-game the power of your disabling coupled to your unmatched mobility (plausible exceptions for Tinker, Furion and Meepo with BoT) will help your team win teamfights, gank, countergank and push. You will rely on Tornado for most of your pushing and help win teamfights with Deafening Blast and EMP. Your Ice Wall and Ghost Walk are also going to be pretty good slows due to the strong W and Q in this build. Late-game this build converges with every other Invoker build except that you're faster.

Level 01 - Exort
Level 02 - Quas
Level 03 - Invoke (invoke Cold Snap)
Level 04 - Quas
Level 05 - Quas
Level 06 - nothing
Level 07 - Quas and Invoke (invoke Ice Wall)
Level 08 - Wex
Max Quas
Max Exort
Max Wex
Get Invoke as possible/desired

I generally keep invoke at level 2 for quite a long time since this build doesn't cycle through spells much. If you'd like, feel free to get another level earlier than I do (for Ghostwalk, Forge Spirits).


Core Items:

The first few items are there to help with your paper HP. Phase is gotten to aid you in placing your spells (notably Ice Wall). The damage boost is also pretty impressive with Exort active.

Extension Items:
Blink Dagger lets you place a perfect Ice Wall in every battle. It'll also help you understand the usefulness of Blink Dagger in a serious Invoker build for positioning. The added mobility and situational escape skills are a bonus.
Shiva's gives you an additional AoE slow to increase chaos. It is a great survival item against physical DPSers and does wonders for your terrible armor. It also provides generous mana and an additional AoE nuke for pushing. Keep in mind that ms can't go below 100, so save Shiva's until after the enemy leaves the effect of Ice Wall.



Your job with this build is two-fold. Early through mid-game, you roam and keep enemies down. You do this mostly by casting cold snap on them and beating on them. Put an icewall across the escape route and have an ally join you in the beatdown. Your high-level Quas should be used to heal between ganks.

Starting mid-game and going through late-game your job description includes causing the enemy team to fight at a disadvantage due to AoE slows. This means Ice Wall, Shiva's and Ghost Walk are used to slow the enemy to a crawl. Once you have level 4 Exort, you can also push (if the opportunity presents itself) with Spirits and Shiva's for AoE creep damage.

Level 01 - Exort
Level 02 - Quas
Level 03 - Invoke (invoke Spirits)
Level 04 - Exort
Level 05 - Exort
Level 06 - Quas
Level 07 - Invoke (invoke Cold Snap)
Level 08 - Exort
Level 09 - Quas
Level 10 - Quas
Level 11 - Wex
Max Exort
Max Quas
Max Wex
Get Invoke as possible/desired

I generally keep invoke at level 2 for quite a long time since this build doesn't cycle through spells much at all. This build focuses a huge amount on forge spirits and ignores almost everything else. It's called an extreme build for a reason. Cold Snap, combined with you, an ally and spirits can do heavy damage. Meteor is a fairly good spell choice in order to wipe out creep waves for quick pushes.


Core Items:

The first few items are there to help with your paper HP. While RoB is usually needed on most summoner heroes, Invoker is an exception. Quas provides his spirits with armor and Exort provides them with both range and HP, which means they don't need that much help. Necronomicon provides the spirits with minor attack speed, a significant ms boost and 2 more friends to beat on heroes/creeps/buildings.

Extension Items:
Boots of Travel give you a huge amount of mobility. They let you and your army be where you need to be at any point in time. After this point, your summoning power is maxed out and you should transition to a different role with your coming items. Use BoT to push with meteor, blast and your entire army at any lane that looks vulnerable.



Your job with this build is to push. You have a strong, portable army that can do heavy damage and you should use it to raze buildings to the ground. In team fights, contribute by doing damage with your spirits/necrowarriors and casting meteor/deafening blast to add chaos.

Level 01 - Exort
Level 02 - Wex
Level 03 - Invoke (invoke Alacrity)
Level 04 - Exort
Level 05 - Exort
Level 06 - Wex
Level 07 - Invoke (invoke Chaos Meteor)
Level 08 - Exort
Level 09 - Wex
Level 10 - Wex
Level 11 - Wex
Max Exort
Max Wex
Max Quas
Get Invoke as possible/desired

I generally keep invoke at level 2 for quite a long time since this build doesn't cycle through spells much at all. This build focuses almost purely on your (not-so-stellar) potential as a dps carry. You'll be getting Alacrity with heavy Exort early on for lane control. Later on you'll get Wex to increase your attack speed (it's a better way to gain dps given your high raw damage as you go for Deso). I suggest maxing Exort first to keep Meteor relevant, but maxing Wex first to have the highest possible dps is reasonable too.


Core Items:

The first few items are there to help with your paper HP. Treads is the clear choice for the attack speed bonus and the bit of additional hp (you'll get focused once they see your dps). Then Deso. Well, Deso's where you give up any pretense of survivability or casting and go for an all-out glass cannon build.

Extension Items:
Lothar's is a reasonable way to help you survive despite being fragile and a high-priority target (due to your high dps). As with any time I suggest Lothar's, it's about the phase and the huge MS boost, not the invisibility. That's just an added bonus if your enemies are foolish. Combined with your high Wex in this build, you can very easily achieve max ms. When you are about to get focused, make the enemy have to run through the rest of your team in order to get to you.
HoT is the only item that can really "fix" your fragility. Even after HoT, your hp is subpar, but at least it can no longer be called pathetic.



Your job with this build is to do damage. You put Alacrity on yourself and start attacking. Toss a Meteor into the fray to break the enemy's formation and give yourself time to dps. You'll need some good support to make this work.

Level 01 - Exort
Level 02 - Invoke (invoke Sun Strike)
Level 03 - Exort
Level 04 - Wex
Level 05 - Exort
Level 06 - _____
Level 07 - Exort and Invoke (invoke Chaos Meteor)
Level 08 - Quas
Level 09 - Exort
Level 10 - Quas
Level 11 - Exort
Level 12 - Quas
Level 13 - Exort
Max Exort
Max Wex
Max Quas
Get Invoke as possible/desired

This build is all about damage. As a result, we need to crank Exort up as fast as possible to gain a powerful Sun Strike, Chaos Meteor and Deafening Blast. This build's, and indeed Invoker's, most massive nuke is performed by sending out a Chaos Meteor and then using Deafening Blast to push the enemy along it's path. Those two spells and Sun Strike should be what you work on in this build.


Core Items:

The first few items are there to help with your paper HP. Either Phase or Treads makes sense for your Boot upgrade - we need the early Dagon and can't wait to farm BoT. Finally, we finish our core by getting Dagon 1 to give ourselves another nuke. Note that one weakness of this build is that we get no mana regen - feel free to buy a Sobi Mask or Void Stone if you feel it's helpful.

Extension Items:
Leveling Dagon further is the logical choice to make this build more extreme. While the upgrades are expensive, recent buffs to Dagon make it more viable. You can skip this and go straight for Shiva's if you'd like.
Shiva's completes your set of nuking items. It also provides you with a comfortable mana pool.
Refresher is the final boost you can give to your nuking power. Assuming you have enough mana, it doubles your ability to do damage with your spells. I'd only recommend this /after/ Shiva's due to the stress it puts on your mana pool.



The nuking build is meant to nuke. Early game, aid ganks with your powerful sun strike. Later, strike fear into the enemy with Chaos Meteor and get kills by combining it with Deafening Blast. Once you have Dagon, your potential burst damage is huge. That said, it's not very reliable. Both Sun Strike and Chaos Meteor require specific situations to effectively deal damage.