Oracle

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. Other sources do bonus damage though, 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 Alchemist after he achieves the second level of his ult), Oracle can actually be a formidable auto-attacking hero.
 * 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.

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".

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 (the first in written order, though) 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 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 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.