Tuned 30/0/21 · 1 min is the build for a one-minute single-boss fight, split 30/0/21: Affliction down to 
Shadow Mastery, then Destruction for 
Bane, 
Ruin and 
Agonizing Flames.
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0/10535002013510005--0550025103It is a Shadow Bolt build with a full set of dots, not the drain build Blizzard's notes describe. 
Wrack, the 31-point channel Blizzard means as Affliction's main filler, isn't in it, and none of our simulated rotations casts Wrack yet, so it has no number here. Its own data suggests it would lose: 36 damage a second for six seconds, against 253 to 283 for a 2.5-second Shadow Bolt, and each adds about 86 % of your spell power.
Why these talents
Bane takes half a second off Shadow Bolt, down to 2.5 seconds, and off 
Immolate, down to 1.5. With Shadow Bolt doing half your damage, that is the build's biggest talent on one boss, worth 9.2 %. Against three bosses, where you cast fewer bolts, it falls to 4.3 %.
Improved Shadow Bolt turns your Shadow Bolt crits into a debuff. Each one puts Shadow Vulnerability on the boss for 12 seconds: 20 % more damage from your own Shadow spells, Corruption's and the banes' ticks included. Forever took away its charges, so other players' hits no longer use it up. On a three-minute single-boss fight that comes to 7.3 %.
Ruin and Agonizing Flames are why the build goes deep into Destruction. Shadow Bolt counts as a Destruction spell, so Ruin's five points make its crits deal double damage instead of one and a half, and Agonizing Flames adds 10 % to it, to Immolate and to Searing Pain. Ruin is worth 5.5 %, Agonizing Flames 5.4 %.
Suppression is 5 % hit for every spell you cast, worth 5.2 %. Your gear's hit adds to it, and your Succubus takes all of your hit as its own. The 20 % threat cut comes free.
Malevolence adds 5 % crit to your Shadow spells, worth 4.2 %. With Improved Shadow Bolt, each extra Shadow Bolt crit also renews Shadow Vulnerability. 
Pandemic makes Corruption and the banes crit for double, like Ruin does for Shadow Bolt. It is worth 2.7 % on one boss and 5.5 % on three, where the dots carry the fight.
Shadow Mastery is 5 % more Shadow damage, half of what it gave in Classic, worth 3.5 %. 
Malediction, new in Forever, adds 5 % to every periodic tick of your spells, worth 1.7 %. It sits on the second row, where you need the points anyway.
Improved Corruption takes 0.4 seconds off Corruption's cast a point and adds 2 % to its damage. At two points the cast is 1.2 seconds, already shorter than the 1.5-second global cooldown, so every point after that adds only its 2 %: the last one in the one-boss three-minute build is worth 1.8 DPS. The three-boss builds take all five, because they cast Corruption about three times as often.
Flexible points
These points barely move the result.
Nightfall: each Corruption tick has a 4 % chance to make your next Shadow Bolt instant. Corruption ticks six times per cast, so it fires about 2 times on a three-minute single-boss fight, worth 0.5 %. An instant Shadow Bolt is also one you can cast on the move.
Improved Life Tap: 20 % more mana from each tap, worth 1.2 % on three minutes. The one-minute builds leave it out, because you start with enough mana for a minute.
Cataclysm: Destruction spells cost 10 % less mana, worth 1.7 % on three minutes. The one-minute and three-boss builds spend these points elsewhere.
Shadowburn: an instant Shadow hit on a 15-second cooldown, worth 2.8 % on a one-minute single-boss fight. It costs a Soul Shard, which our simulator doesn't track, so bring shards for every cast.
Amplify Curse: 50 % more base damage on your next Bane of Agony, once every three minutes. Only the one-minute builds take it, where it is worth 1.0 %.
What each talent is worth
To get these numbers we ran the build again without each talent, on the same simulated fights. Talents feed each other, so the values don't add up to your damage. When you move a single point, the last-point column is the one that matters.
On every fight
The one-boss builds keep the 30/0/21 shape and move a few points. The one-minute build drops Improved Life Tap, Cataclysm and a Nightfall point for 
Improved Bane of Agony, Amplify Curse, Shadowburn and two points of 
Aftermath. The two- and three-minute builds against three bosses go 33/0/18: they drop Improved Shadow Bolt and Cataclysm and fill Improved Corruption, Improved Bane of Agony and Aftermath, whose 50 % on Immolate's impact pays off when you cast Immolate on every boss.