SM/DS

General Build Information
The 2 main talents that this build focuses on are Shadow Mastery and Demonic Sacrifice. As such this build features high damage output (SM) in combination with even higher damage output (demonic sacrifice: Succubus) or increased standing power in long fights (demonic sacrifice: Voidwalker). As this build focuses on buffing the warlock at the cost of the demon it is only showing its real strength in raid-groups.

Advantages

 * similar damage output as SM/Ruin but a little more versatile because of the different buffs you gain from sacrificing your pets
 * if you sacrifice the succubus you gain a whopping 25% extra damage on all the shadow damage you dish out (+10% from SM, +15% from DS-Succubus)
 * if you sacrifice your voidwalker an slap on a Siphon Life (warlock talent) your health regen (with Demon Armor (Classic)) will be around 55hp/s (without extra regen gear). I won't need to tell you what that means in a long boss-fight.
 * instant demon summoning gives you the opportunity to adapt to a changing situation quickly
 * better aggro management due to lack of Ruin and longer Shadow Bolt casting time
 * improved healthstones

Disadvantages

 * longer Shadow Bolt casting time, lesser crit chance and no Shadowburn makes this build not ideal for PvP situations
 * the strongest without a pet - so if there is no other locks in your group that have their imp out for the stam buff, you will be forced to forfeit one of your best abilities
 * high shard usage

Specific Talent Build Examples
The variations in this build are the same as in other builds in the Affliction and Demonology trees. I prefer the following setup:


 * A lock for every season

It gives you all the niceties in the affliction tree with improved Drain Life and Fel Concentration for drain tanking, instant corruption and Nightfall (warlock talent), as well as Grim Reach and Curse of Exhaustion to bring in an extra Shadow Bolt while the mob is charging at you. Improved Life Tap is a must!

In the Demonology tree, we increase our STA with Demonic Embrace, and keep our main pets up to speed with improved imp, improved void, and fel stamina (just in case we are forced to use the imp, or want to solo something big). Furthermore, there are improved healthstones for the tanks to make up for the missing blood-pact, and fel concentration as well as master summoner for increased versatility.

Basic Combat Information
With this build it is hard to paint a 'typical combat' scenario as the spells your are likely to use very much depend on the demon you are using. In general, apart from the classical drain tanking technique described elsewhere for handling ordinary mobs, this build is tuned for the long boss fights you are faced with in end-game raid instances like Molten Core and Blackwing Lair. For these you will have to chose between either going for damage or sustainability: sacrifice your succubus and start spamming Shadow Bolts if you wanna maximize your DPS - slap on siphon life and life tap if mana becomes an issue. On the other hand, in fights where your mana consumption is likely to become compromised by a high likelihood of you taking damage (for example if the boss you are fighting has an AoE attack) you can make yourself invincible by sacrificing your voidwalker, use siphon life, and keep spamming Shadow Bolts until the end of days (with short life tapping breaks). In the unlikely event that your health for some reason or other will go down to critical levels, a couple of drain lifes will not only restore your health bar, but is also likely to proc nightfall to get you back on the damage track. For both variants you should of course use corruption and any other curses that you might have been assigned to.

General Feel
If you like the feeling of not having to care about damage because your health is regenerating quicker than you can life tap, while at the same time having the option of doing large amounts of damage (at least in long fights) this is the build for you. However, if you are a fan of high crits and instant damage, you should maybe opt for SM/Ruin.