Immolate

Immolate is a warlock hybrid spell spell that deals both direct damage and damage over time, with an emphasis on the latter. It is one of the common DoTs warlocks often place of their targets.

This spell is the quintessential cornerstone of the Destruction tree. It increases the damage of your Incinerate spell by a substantial margin, and is one of the spells that gives you access to casting Conflagrate, and the Fire and Brimstone talent allows it to increase the damage of Chaos Bolt, as well as further increase the damage of Incinerate.

Table
Immolate is available at level 3 for.

Talent improvement
Bane will lower the cast time of Immolate by up to .5 seconds at max rank. Talents like Emberstorm at max rank will increase the amount of fire spell damage that applies to the spell by 10%.

Immolate is a Destruction spell, and thus gains the benefits of Ruin.

Tips and tactics
When tanking mobs with your pet (either Voidwalker or Felguard), save casting Immolate until the end of your DoT rotation. Not only does it have the shortest duration, but as it deals initial damage, it generates the most threat and could possibly pull the mob to you.

However, there is an exception to the above tactic. If the Warlock is soloing, and, the tactic is that of a Warlock Tank and the Warlock is expecting a long fight, casting Immolate to start the fight may be beneficial for two reasons. First, the Warlock avoids potential interruption of the 2 sec. cast time when offering an opening Immolate. Secondly, if the fight is expected to be in the 25-35 sec. range, a second Immolate can be cast, maximizing the likelihood of conducting a mana-efficient battle (2.12 dmg. per mana at max rank)