Warlock

Demnok Lannik the Warlock is a ranged intelligence hero commonly noted for being a versatile support known for creating chaos in the battlefield while at a safe distance. His Shadow Word ability makes for an excellent heal as well as a decent harassment tool, which combined with his physical attack helps him to ward off any enemies and keep his friends safe. He also possesses a considerable presence in team fights, as Fatal Bonds spreads damage dealt by his allies to all enemies affected by it and his Upheaval is a channelled Area of Effect spell that slows foes caught in it by up to 84%. His ultimate, Chaotic Offering allows him to summon a massive Golem to do his bidding, stunning anyone caught in a large area when it is summoned.

Tips

 * In general, Warlock should be played as a support hero rather than as a farming hero. As such, it should default to him to purchase the, and upgrade it as needed, as well as s and s throughout the course of a match.
 * is a very powerful teamfight ability, as it can cause area-of-effect spells that hit all bonded units to deal more than twice its listed damage to each foe. While it should not be the first spell that you max out, it should still be a priority spell to level up, and cast as early as possible in a teamfight.
 * When deciding at what time to skill Fatal Bonds, it should be kept in mind how active your team will be in engaging the foe in major teamfights. If you do not expect to encounter 5-vs-5 teamfights often, then it is safe to level up your other abilities first. However, if the enemy team is employing an early pushing strategy, threatening them with large amounts of shared damage that is magnified by area-of-effect nukes can give them pause.
 * Keep in mind that Fatal Bonds damage is reduced by each individual target's resistances, so dealing reduced damage to an enemy with high armor or magic resistance will not propagate that reduction to other shackled units. However, the reverse also applies, as dealing large amounts of damage to an enemy with little armor or magic resistance will not amplify the damage shared by an enemy that is more resilient.
 * is Warlock's most flexible spell, capable of healing allies or damaging enemies. It should be the first spell to max out in most situations, as it can serve as a powerful nuke or a life-saving heal at any point in a match.
 * Shadow Word costs 90 mana to heal/damage 165 HP at level 1, and will consume almost a third of your mana pool to do so. Therefore, it is wise to avoid casting the spell at level 1 if at all possible, as it becomes much more efficient with additional levels.
 * Beware that although Shadow Word can heal a single ally by almost 500 HP, it takes time to do so. Therefore, it should be cast as early as possible when a situation arises, so that your ally is not put in a situation where they might not have enough HP to survive long enough to benefit from the healing buff.
 * is a very large area slow with a very long cast range, capable of inflicting a slow from up to 1850 range away. Its drawback is that the slow takes time to build up, and ramps up very slowly at early levels. Try to avoid channeling the spell unless it is at least level 2, as it is a waste of mana.
 * Keep in mind, Upheaval becomes stronger the longer it is channeled, not how long an enemy was standing in it, and that the slow sticks on the target up to 3 seconds after leaving the area. Because of this, it is more effective to pre-emptively channel Upheaval to give it time to build up, rather than casting the whirlpool on top of a foe.
 * Upheaval's primary use comes right after initiating or counter-initiating with your ultimate and Fatal Bonds, as you can then channel Upheaval to greatly hinder enemy heroes' ability to escape while your Golem goes to work on them. The enemy can choose to expend one of their disables to interrupt your channeling, however this can also be a positive outcome as they will then have less to expend on your teammates.
 * Upheaval can also be used effectively against solo targets once it is high enough level and combined with a leading stun to give you time to build up the slow. Provided that your teammates have enough damage output, slowing the enemy down can be much more beneficial than right-clicking him.
 * In a pinch, Upheaval can be used to cover retreats, or for area denial. Casting the spell on an area that the enemy wants to traverse can give them pause, as walking into an active Upheaval will slow them down much more than if it was cast on top of them. This can be useful for giving teammates space to run away, or for preventing the enemy from entering an area that they wish to go (such as pushing up high ground into your base, or Roshan's pit).
 * Beware, Upheaval is a percent movement speed slow, and as such can be ignored by certain abilities such as Centaur Warrunner's, Weaver's , Dark Seer's , and so on. Be sure that you know what abilities the enemy has that can ignore Upheaval's debuff.
 * is your most powerful teamfight spell, as it will stun all enemies in the impact area and summon a Golem to do your bidding. This can often be enough to completely disrupt anything that the enemy is doing and give your team enough time to capitalize on the situation.
 * It can be useful at times to cast Shadow Word on your Golem, in order to heal it and prolong its lifespan. The longer the Golem is alive, the more damage it can deal.
 * When chasing fleeing heroes with your Golem, don't stop to auto-attack them. Instead, keep it moving with them, so that the Permanent Immolation can do its damage.
 * Do not let the Golem die needlessly to the enemy, since its gold bounty is quite high. If it's the last remaining unit for your team in a fight, have it flee unless you can ensure a kill. Having it die against creeps or towers is better than allowing an enemy hero to last-hit it.
 * Beware, 's active purge can instantly kill summoned units, your Golem included. If you know that the enemy has one, it is wise to try to bait out the purge before casting your ultimate, or try to rush an Aghanim's Scepter to ensure that you have at least one Golem to use on the enemy.
 * Warlock can benefit from building many other items other than those listed as recommended:
 * As noted earlier, Warlock should generally carry at least some of the support duties on his team. This means that, , , , and other support items such as and  should all take priority.
 * synergizes well with Shadow Word, as it performs many of the same roles and augments Warlock's flexibility further. It is useful to build if you do not intend on buying a Bracer as the Strength and mana regen are very useful, and can be useful to purchase if nobody else on your team can reliably build an Urn.
 * has a myriad of uses for Warlock. As a ranged support he can use it to support a carry from a distance either by placing the debuff on an enemy or by placing the buff on an ally. The same can be applied to the Golem, either to extend its survivability or weaken its target. Finally, it can be used on Roshan to help your team kill him faster.
 * is a good utility item on any support hero, and is no exception for Warlock. While Warlock is not very demanding on positioning, the ability to quickly displace yourself or a teammate/enemy in various situations can be very important.
 * can be helpful if Warlock is constantly being focused down by the enemy's physical right-clickers. Using Ghost Scepter's active can shield Warlock from Physical damage for some seconds, allowing him to cast his spells as needed.
 * can be useful to purchase if you intend on casting Upheaval frequently. As Warlock often has to channel the spell for at least a few seconds for it to reach full potency, hiding yourself from basic sight can increase your safety and keep the enemy guessing on your location, as the spell's cast range allows you to employ the spell from a fairly safe distance and from multiple directions.

Trivia

 * In DotA, Warlock's ultimate is named Rain of Chaos and the summoned unit was called an Infernal, a hulking golem with green-colored flames. Both names were changed in the transition to Dota 2 to avoid copyright conflict.
 * Warlock is related to and  Axe, as he comes from the Oglodi tribe.
 * Warlock's response " Warl_death_11.mp3 Just for that, I'm unfiending you." when killed is probably a play on "Unfriending you" an action in the popular social network Facebook where a person removes another from their friend list.
 * The response " Warl_respawn_11.mp3 Bloodied but unbowed" when respawning is a reference to William Ernest Henley's poem "Invictus".
 * Fatal Bonds' sound effect is based on this Warl_incant_24.mp3 otherwise unused voice line.