Oracle

Nerif the Oracle is a ranged intelligence hero that decides the fate of allies and enemies, rendering allies invisible and protected by the unreliable prophecy of his ultimate, False Promise. Oracle can also deal lots of damage since Oracle's skillset has a versatile range of combos. One instance is that of burning enemies with Purifying Flames, rendering their weapons useless by the judgement of Fate's Edict. The healing flames are then purged by Fortune's End. Knowledge of Oracle's skills is key to use him at his full potential; one mistake can potentially seal the fate of your allies.

Tips

 * All of Oracle's spells have great direct synergy with each other.
 * The initial damage from is fully blocked by the 100% magic resistance from, turning it into a strong heal for allies. But don't forget that other damage types will do increased damage and it also disarms your target, so it can backfire if timed poorly.
 * is purgeable, so can remove the healing effect of it, turning it into a strong instant nuke with no heal for enemies.
 * doubles all healing received during it, including the healing of, making it heal a total of 198/216/324/432 health if the spell's damage is taken into account.
 * , and  together on one ally effectively makes it heal for 198/396/594/792 health once the ultimate expires, since the damage is blocked by the 100% magic resistance and the heal doubled by the ultimate.
 * in combination with, or  can grant a hero 100% magic resistance and 100% resistance against physical damage, so only pure damage is able to harm them.
 * Owing to the fact that Oracle has the lowest natural base attack time in the game (surpassed only by a level 2 ), one is inclined to think that Oracle can actually be a formidable auto-attacking hero but playing him as such is hardly advisable because he is far greater as a support or nuker.
 * Keep in mind that while Oracle's healing potential is great with the right items, as seen above, he needs to pull off various spell combos to be truly effective. Although the mana costs of his abilities are moderate, with their low cooldown all of his combos are almost spammable. Without cost-effective easy build-up mana regen items like, , you will find yourself with no mana and not being useful very often in the mid-game.
 * can purge the healing from, and since the cyclone lasts for 2.5s, you can effectively cast it twice on the enemy, purging it again with.
 * Note that has a slow projectile, while ' effect is instant. This means you can cast  first, and before the projectile hits, use . This will prevent the target from healing at all by the  buff.
 * is not purgeable, except by his own . This makes a great skill versus heroes lke,  and . Don't forget though that spell immunity can dispel it, making it great against heroes who usually don't want to buy an.
 * Before a fight is about to happen, specially when pushing or defending your base, keep casting on your carry. Since it has a short cooldown, you can ensure he will start the fight with at least 2 instances of healing (the healing is stackable).
 * removes most negative buffs from the target, like does. Try to save it for when your target gets stunned. This way not only you will save him, but also mitigate the disable cast on him.

Trivia

 * Oracle made his first official Dota 2 appearance in the comic The Contract, revealed on the 14th of November 2014 in the official Dota2 blog.
 * Mike Shapiro (Oracle's voice actor) is also well-known for voicing Barney Calhoun and G-Man, two prominent characters in the Half-Life series, with his lines of Orac_randomprophecies_10.mp3 "Prepare for unforeseen consequences", and Orac_respawn_10.mp3 "Is it really that time again?" referencing those of G-man's lines in Half-Life 2: Episode 2, and Half-Life 2 respectively.
 * The line Orac_move_11.mp3 Orac_move_19.mp3  Orac_death_15.mp3 "So it goes" is a reference to the novel Slaughterhouse-Five, by Kurt Vonnegut. In the novel, it is a phrase used by the aliens, known as Tralfamadorians, who perceive all time simultaneously.
 * The line Orac_firstblood_01.mp3 "First blood! Out of fifty possibilities, that was my preferred" is because there actually are 50 possible first bloods (each of 10 heroes can be killed by any of the 5 opposing heroes).
 * Oracle's spell and his phrase Orac_purifyingflames_02.mp3 "I must harm to heal." may be a direct play on the medical principle "Primum non nocere", which basically means "First, do no harm".
 * The line Orac_kill_08.mp3 "Ask again later." is a reference to an answer of the Magic 8-ball, a toy used for fortune-telling.

Prophecies

 * The prophecy line for Lion Orac_prophecies_051.mp3 "Fear neither witch, nor wardrobe. Tis a demon beast that fingers your demise." is a reference to the second book in The Chronicles of Narnia book series by C.S. Lewis, titled The Lion, the Witch, and the Wardrobe.
 * The prophecy line for Void Orac_prophecies_035.mp3 "You ought to read Chronosphere of a Death Foretold. It's a prophetic book" is a reference to the book called Chronicle of a Death Foretold, written by Gabriel García Márquez.
 * The prophecy line for Viper Orac_prophecies_104.mp3 "V is not for visions of victory, but for a victim of a vicious viper." is a reference to the quote of V for Vendetta.
 * The prophecy line for Chaos Knight Orac_prophecies_017.mp3 "Beware the knight who commandingly demands: do you even rift?" is a reference to the internet meme "Do you even lift?"
 * The prophecy for Ember Spirit Orac_prophecies_036.mp3 "I foresee four flames." may be a reference, both in content and length, to the fact that most of Ember Spirit's spoken lines are four words long, or to the four of "him" – the real one and three remnants.
 * The prophecy line for Morphling Orac_prophecies_059.mp3 "No empathy test can save you from the watery replicant." is a reference to Do Androids Dream of Electric Sheep?, where human-like androids called replicants can only be distinguished from human beings through an empathy test called the Voight-Kampff test.