Kael'thas Abilities and Strategy

• Since Kael'thas lacks any type of mobility, positioning is extremely important. Once an enemy Hero is attacking him, he must rely on his allies to assist him. Protect Kael'thas by being proactive and keeping a distance.
• Verdant Spheres should be used with Flamestrike when Kael'thas needs waveclear.
• Gravity Lapse should only be empowered with Verdant Spheres to catch an enemy Hero hiding behind a minion or to stun multiple enemy Heroes.
• Phoenix can be used to zone enemy Heroes, kill Mercenaries, clear Minion waves, and to siege or defend Forts and Keeps. Its relatively low cooldown encourages Kael'thas to use it liberally.
• Channel Pyroblast behind walls or Kael'thas' frontline. Try to use it proactively and early in fights, rather than saving it to finish enemies off.
• Gravity Lapse is difficult to hit. Take the time needed to land it, as Kael'thas is defenseless if it misses the desired target(s).

Verdant Spheres adds a level of depth to Kael'thas that few other Heroes possess. However, it only modifies his abilities linearly, such as increased damage, rather than giving them a totally new function. This makes Kael'thas' empowered abilities function similarly to their default ones, but with increased effectiveness. It is up to you, the player, to decide which empowered ability is most effective in each situation and use it accordingly.

Flamestrike is used mostly to poke from a long range and to waveclear. Of Kael'thas' three basic abilities, Flamestrike should be the ability that he empowers most often with Verdant Spheres to deal maximum damage in team fights. Since there is a delay between casting Flamestrike and it dealing damage, aim it where Kael'thas' target will be, and not where they currently are. Doing so will help him strike moving targets. Casting Flamestrike on targets affected by crowd control, like Gravity Lapse, can make it easier to hit the desired target.

Living Bomb is a single-target, damage over time ability that then explodes, dealing AoE damage. It is very powerful throughout the game, but it is especially impactful once full team fights begin to occur and enemies begin to stack. Living Bomb can be used when empowered with Verdant Spheres, effectively reducing its cooldown to 6 seconds (the cooldown of Verdant Spheres), although Kael'thas will generally not have two targets within range to use the 2nd charge on. This makes Living Bomb fantastic at trading versus enemies, since it costs no Mana, is targeted, and is only on a 6-second cooldown. Generally, Kael'thas should refrain from using Living Bomb without Verdant Spheres or from using Living Bomb a second time after an empowered Living Bomb, unless the additional damage is needed to secure a kill.

Standing as far back as possible from team fights is the best precaution Kael'thas can take to ensure that he is safe while trying to cast his abilities. Kael'thas should only get within range to cast Living Bomb if he is confident that the enemy team is unable to get to him, his allies will protect him, or casting Living Bomb will win the fight.

Gravity Lapse is Kael'thas' only source of crowd control, so it is important that he use it sparingly. Gravity Lapse's large hitbox means that it can often hit unintended targets, like Minions, summoned creatures, or other Heroes if he is not careful. Empowering Gravity Lapse with Verdant Spheres can help alleviate this issue by allowing Gravity Lapse to stun the first three targets and for a longer duration. In this way, Kael'thas can hit Heroes hiding behind minions or Tanks, but Gravity Lapse's short range means that he must be standing very close to the enemy Heroes to Stun them, which can be fairly risky.

Gravity Lapse can be used both offensively and defensively, but it is always more effective when there are allies nearby that can follow-up with damage or crowd control of their own. Kael'thas can use Gravity Lapse to setup ganks during the early game, but he should be wary of doing so later into the game, and instead use it to peel for himself or in combination with his allies' abilities.

Using Verdant Spheres to empower Gravity Lapse is situational. While Gravity Lapse could Stun up to three enemy Heroes when empowered, it might be better to simply empower Living Bomb or Flamestrike, allowing Kael'thas to deal more damage. This is especially true if there is no follow-up from his allies. Sometimes empowered Gravity Lapse is best used to Stun a single Hero that is hiding behind minions. Whether or not to use empowered Gravity Lapse depends on a number of factors, and ultimately, it is up to the player to decide when to use it.

Phoenix is a high-damage, AoE ability. While it is mainly used to deal damage in team fights, it is also has many other uses. Phoenix can be used to zone enemy Heroes, kill Mercenaries, clear Minion waves, and to siege or defend Forts and Keeps. Its multitude of uses is due to its relatively low cooldown of 60 seconds. Since Phoenix has such a low cooldown, it should be used much more liberally than similar Heroic abilities.

Phoenix's biggest downfall is that it lacks any form of crowd control and enemy Heroes can easily walk out of the affected area. This is why it is important to use Phoenix for the express purpose of discouraging enemies from walking through it (to defend an objective), or in combination with allied crowd control, which can be used to force enemies to stay within Phoenix's radius. However, that is just to use it most optimally, using it in the middle of a team fight with no crowd control is often perfectly acceptable.

Pyroblast deals the most single-target damage of any ability in the game. It is able to do 40% or more of a squishy target's maximum health, and in conjunction with Kael'thas Basic Abilities, he possesses more than enough damage to 1-shot the majority of Heroes in the game. However, Pyroblast has a 1.5-second channel time, during which enemies can move out of range or interrupt Kael'thas' channelling, not to mention he is rendered immobile and at the mercy of his enemies, so it is important to never channel the ability in positions where he is vulnerable. Try to use Pyroblast from behind a wall or a Tank. Not only will this protect Kael'thas, but it will also make it less likely that the enemy team will notice him and interrupt him or run out of range. It is important to note that for all intents and purposes, Pyroblast is effectively a single-target ability. As soon as an enemy Hero identifies that they have been targeted they will attempt to flee, especially if they are a Hero with low maximum health. Pyroblast's extremely slow travel speed gives the enemy team plenty of time to spread out to prevent any splash damage.

Although Pyroblast can be an effective finisher, most enemy Heroes will flee out of your range when their health gets low. This is why it is important to begin channelling Pyroblast before your target leaves the fight, but doing so in the midst of a fight can be difficult, since channelling leaves Kael'thas vulnerable to Assassins and interrupts. Using Pyroblast to initiate a fight can help alleviate this, since the enemy team's frontline Heroes will usually not yet be in position to stop him.

There are numerous abilities that can reduce or completely negate the fireball. To use Pyroblast optimally and prevent it from being wasted, it is important that these abilities are identified. For example, if the enemy team has a Nazeebo with Ice Block, Kael'thas should never target him with Pyroblast, unless Ice Block has already been used. Otherwise, he is trading Pyroblast for Ice Block, which is rarely a favorable situation. Below is a list of some of the abilities that effectively counter Pyroblast (not including heals or blinks):

• Anub'arak's Burrow Charge;
• Brightwing's Phase Shift;
• Chen's Fortifying Brew and Storm, Earth, Fire;
• E.T.C.'s Stage Dive and Show Stopper;
• Illidan's Metamorphosis and Sixth Sense;
• Murky's Safety Bubble;
• Rehgar's Ancestral Healing;
• Tassadar's Plasma Shield, Dimensional Shift, and Archon;
• The Lost Vikings' Jump! and Longboat Raid!;
• Tyrael's Righteousness and Sanctification (for allied Heroes);
• Zagara's Nydus Network;
• Zeratul's Void Prison (for allied Heroes);
• Ice Block.