Death Knight

The death knights are a heavily armed, highly experienced race or class in World of Warcraft. They no longer serve the Lich king, but they still possess highly effective magic that they learned from their time with the lich king.
The death knights are skilled in melee attacks and they also mix the melee attacks with frost and shadow spells that are ranged.
They have blood abilities that that help them heal themselves which makes them a hybrid class similar to Druids, which is quite useful when you have melee attacks, because you are also susceptible to damage because of your distance from the enemy. The death knight hero class begins at level 55. They are allowed axes, two handed swords, pole arms, swords, one handed maces and two handed maces.

The rune system is a resource mechanism for the death knight; a skilled death knight can make timely use of his runes to maximize his or her damage dealing or other abilities. You will be able to place 6 runes in any combination of unholy, frost and blood. The death knights have a rune system from which they can gain nearly unlimited amounts of energy which is great for harvesting gold in WoW.

The abilities of the death knight in World of Warcraft are many in number. Blood presence is one such ability, in this ability the ability increases the damage output and restores a percent of the damage as health for the death knight. Frost presence reduces the damage percentage taken by the player, but it increases the threat to the knight. The unholy presence increases the speed of the attack but also increases the cool down time for the death knight abilities.

Death coil is another ability in which the death knight can damage the enemy units or heal friendly units, much like warcraft 3. Army of the dead actually raises a temporary army of undead warriors. Raise dead raises fallen allies that help you fight.
Grip of death forces the enemy to attack you much like taunt. Chain strike, blood strike and blade strike are also other abilities of the death knight.

The death knight in WoW as powerful as he may be also has some weaknesses as the death knight depends too much on spells and thus, has quite a low defense which could be exploited by a ranged attack class such as hunters. They also have a huge dependence on the runes. They cannot use shields or ranged weapons, due to this the death knight can take a lot of damage in 1 on 1 combat which is ideal for solo play in WoW or even better in a 2 man team with a mage for example.

The death knights have certain obvious limitations and advantages in PvP combat, they have a low defense and are melee in nature, this can be a limitation, if the death knight is playing a character that has ranged weapons such as a priest or a mage then the death knight has the advantage of close range attack but can be easily be killed from far due to a bad defense.
If the fight is against another melee character then the death knight has chances of winning by using his magic abilities mixed with his melee attacks. The death knight also fares quite well in PvM due to his rare mixture of abilities.

The death knight should take quests that do not involve ranged creatures attacking them because it can be disastrous due to their low defense.
In conclusion the death knight is a versatile character that is able to fare very well in PvP and fare quite well in PvM.