Destruction gives up its demon before the pull and spends the fight casting 
Shadow Bolt. 
Demonic Sacrifice on the Imp now gives 15 % more Shadow damage, and the bolt alone is 37.0 % of your damage on a three-minute fight. Between bolts you keep 
Immolate, 
Corruption and a bane on the boss, and 
Life Tap turns health into mana. The two- and three-minute build also presses 
Conflagrate and 
Shadowburn on cooldown: through 
Shadow and Flame, each gives the other school 10 % more damage. On a one-minute single-boss fight the build does 746.7 DPS, 17th of 25 damage specs.
On a one-minute fight the best setup isn't the Conflagrate build. The search moves those points into Affliction's crit talents, 
Pandemic and 
Malevolence, and drops 
Bane of Doom, whose damage only lands after a minute.
Strengths and weaknesses
Strengths
- Shadow multipliers that stack. On the two- and three-minute builds, Demonic Sacrifice (15 %), Shadow and Flame (10 %), Improved Shadow Bolt (20 % after a bolt crits) and Curse of the Elements (10 %) multiply on every Shadow Bolt.
- Three bosses. Every dot goes on all three, so your damage climbs from 714.6 DPS on one boss to 900.5 DPS on three over the same three minutes.
- The raid's curse.
Curse of the Elements makes the boss take 10 % more magic damage, which every caster in the raid gains.
Weaknesses
- Mid-table everywhere. 15th on a three-minute fight, 17th on one minute and 15th against three bosses, each of 25 damage specs.
- A 16 % hit cap. A level-63 boss resists 17 % of your spells before hit, and nothing past 16 % helps. With
Suppression this set reaches 8.0 %, so the rest of the gap still misses. - It runs on healing. You Life Tap about 12 times on a three-minute fight, each tap costing as much health as it gives mana. Our simulator lets your health run down. In a raid a healer pays it back.
- Long casts. Shadow Bolt takes 2.5 seconds even with
Bane. Our bosses never move, but every step in a real fight costs bolts.
On every fight
Destruction holds roughly the same place on every fight. The one-minute build trades its Conflagrate talents for Affliction's, and on three bosses the dots carry it. Click a fight to switch the whole guide to it.
Races
For the Horde, Troll leads on a one-minute single-boss fight. Undead win the two- and three-minute fights through Touch of the Grave: a tenth of your landed spells drain 5 % of your maximum health from the boss, 1.7 % of your damage on three minutes. Trolls take the one-minute fights, where 
Berserking's 10 % faster casts cover the first sixth of the fight. Orcs are close behind both, with 
Blood Fury on cooldown.
For the Alliance, Human beats Gnome on every fight. Sword Specialization is now 2 % crit with all spells while you hold a sword, and the Alliance set's Sageblade is one. The Human Spirit's 5 % Spirit adds to every Life Tap as well.
What a Warlock brings to the raid
Curse of the Elements is what a warlock adds: 10 % more magic damage taken and 75 less resistance on the boss, for every caster. A Destruction warlock brings no 
Blood Pact, which needs the Imp it sacrifices. The table shows each warlock buff's worth to the damage specs on this fight.
Curse of the Elements+5.8 % to 19 of 25most: Balance Druid +9.1 %
Blood Pact+0.3 % to 3 of 25most: Mutilate Rogue +0.4 %
Changes
The line follows this build's result here across simulator and game-data updates, and the Updates page explains each one.