Energy Twister

Energy Twister is an Arcane spell used by s in Diablo III. It resembles the Druid Twister skill from the second game.

In-game
Energy Twister conjures slow, erratically-moving vortex of energy which deals Arcane damage over time to everything it touches (roughly 6 yards radius), piercing through enemies. Each Twister is created at the player's cursor, moving away from them, anywhere within 60 yards. There is no limit on how many Twisters can be summoned at a time.

On PC and Mac, twisters despawn immediately if they stop moving for whatever reason. This excludes the Wicked Wind twisters, obviously.

Runes:

 * Mistral Breeze: damage type turns to Cold, reduces Arcane Power cost to 25.
 * Gale Force: damage type changes to Fire, affected enemies take 15% more Fire damage for 4 seconds.
 * Raging Storm: if two Energy Twisters collide, they merge into one, dealing 3200% damage over 6 seconds (regardless of the previous duration) in a twice as large radius. Only the lesser Twisters can merge, and only those summoned by the Wizard.
 * Wicked Wind: Energy Twister no longer moves, but damage is decreased to 835% over 6 seconds.
 * Storm Chaser: damage type turns to Lightning. Each cast of Energy Twister grants a Lightning Charge, up to 3 total charges. When a Signature spell (i.e. Magic Missile, Shock Pulse, Spectral Blade or Electrocute) is cast, all Lightning Charges are consumed, and a bolt of lightning is released, traveling in a straight path, hitting for 196% damage as Lightning per tick (multiplied by number of charges) and piercing through enemies.

Non-rune enhancements:

 * Valthek's Rebuke (Legendary Staff): Energy Twister travels in straight path, 80 yards forward. Has no effect with the Wicked Wind rune. Energy Twister also deals 300-400% increased damage.
 * The Twisted Sword (Legendary Sword): for each Energy Twister currently active, their damage increases by 125-150%, to a maximum of 5. The Raging Storm rune is automatically applied to Energy Twister and allows the tornado to merge with 3 additional Energy Twisters.
 * Ranslor's Folly (Legendary Bracers): Energy Twisters pull in enemies from within 30 yards, once every 5 seconds per enemy, and deal 225-300% increased damage.
 * Etched Sigil (Legendary Source): while channeling Arcane Torrent, Disintegrate, or Ray of Frost, the damage of your Energy Twister is increased by 200-250%, and you also cast Energy Twister every second.
 * Delsere's Magnum Opus Set (Set Bonus for 2 items): casting Energy Twister reduces the remaining cooldown of Slow Time by 3 seconds.
 * Delsere's Magnum Opus Set (Set Bonus for 6 items): enemies affected by Slow Time and 5 seconds afterwards take +12500% increased damage from Energy Twister.

Trivia

 * This skill is often used by the Shadow Clones in Realm of Terror, and Zoltun Kulle uses empowered version of this spell during the fight with him.