Planning my DK

The basic premise of the spec is you get the Frost talents which have the greatest effect on Icy Touch: Improved Icy Touch, Glacier Rot, Black Ice, Killing Machine and Deathchill.

Combined with the Frost talents are Unholy talents which further affect Icy Touch: Impurity, Ebon Plaguebringer and Rage of Rivendare (and to a lesser extent Bone Shield and Desecration).

Together, these talents have incredible synergy and give Icy Touch damage approximately equivalent to Scourge Strike and guranteed crits through Killing Machine.

As ShadowFrost, it is often difficult to know which presence to use and good players disagree over what the "default" presence (or the one they use the most) should be.

Blood Presence*offers the hardest hits and highest sustained damage. If your spec does not take Unholy Aura then you wont have a speed bonus in this presence and may want to avoid it. This presence is typically used in games which which take longer (for instance if you 2v2 with a healer and run into another dps/healer comp).

Unholy Presence*offers the highest burst damage at the cost of some sustained damage. This presence is most useful in situations where you wont be able to spend a lot of time on a target before the escape (for instance a paladin kiting away from you with freedom or if a rogue is on you stunning frequently) or when you need to burst. Empower Rune Weapon is much stronger in this presence because the shorter GCD allows you to cycle through runes faster. If you dont have Unholy Aura, this presence should probably be your default.

Frost Presence*offers by far the best mitigation. If your healer needs to drink or you expect a big burst (e.g. the other team bloodlusts) it is crucial to be able to switch to Frost on short notice to mitigate damage.

When you actually get into arena, you will be dealing primary damage with Icy Touch, while snaring targets with Desecration and Blood Boil. Spreading diseases with Pestilence is important to do better overall damage, make dispelling diseases harder and allow Blood Boil snares on multiple targets.

Deathchill will not be consumed if Killing Machine is active, so don't be afraid to pop it any time during a burst attempt. If KM procs then you will get 2 crit ITs in a row.

Corpse Explosion can be a very effective nuke. With Ebon Plague on the target, Glyph of the Ghoul and Ravenous Dead, this ability, when used on your living ghoul, can hit (NOT crit) for 25% of your ghoul's health (+13% from Ebon Plague) which will typically be 5k or more. The downside is the target must not be moving, so its best used on a target you have stunned or otherwise immobilized. Combine this with Deathchilled IT for huge combos.