Unlike other traditional carries like Anti-Mage or Phantom Assassin, he is equipped with a reliable stun and slow from the start with Wraithfire Blast. Wraith King is most often played as a farming position 1.
He is, however, particularly vulnerable to abilities that burn mana, as well as break. However, Wraith King can also be played at a high level of skill, particularly by using active items. He is traditionally popular among new players for his survivability and simple playstyle. His ultimate, Reincarnation, effectively doubles his health in a teamfight, as well as slowing enemies by a large amount. Mortal Strike allows Wraith King to deal 3 times his normal damage, and it can summon skeletons that are useful for pushing and farming. Vampiric Spirit allows Wraith King and other allies to gain lifesteal based on their damage, which can help in teamfights and pushing lanes.
Wraith King is a durable carry with a reliable stun in Wraithfire Blast that also slows and does damage-over-time.