Skeleton King

Ostarion the Skeleton King is a powerful melee strength hero, capable of taking plenty of damage before dying. His ultimate allows him to rise again, acting almost like an Aegis of the Immortal, making him especially difficult to kill. He also has a nuke that deals reliable damage and stun while he is also able to stay in his lane longer because of his lifestealing passive.

Tips

 * Hellfire Blast is a very good nuke, allowing you to disable and slow at the same time. Perfect tool for ganks and team fights. It has a relatively low cooldown, so spam it if you have enough mana.
 * Vampiric Aura allows you to heal yourself simply by hitting enemies. Your melee allies also benefit from it. Scales nicely into the late game.
 * Learning Vampiric Aura during laning phase will shift the creeps equilibrium and you'll be forced to farm and fight under enemy tower. Good for pushing, but hurts your farm and puts you and your allies in disadvantageous position.
 * Critical Strike drastically increases Skeleton King's melee DPS. Synergizes well with Vampiric Aura, healing Skeleton King a big chunk of health every time he crits.
 * Reincarnation revives Skeleton King if he dies during the battle. Always make sure you have enough mana for this ability.
 * Hellfire Blast is usually maxed first and Reincarnation is taken as soon as possible. It's also recommended to take two levels of Stats on early levels to improve Skeleton King's mana pool and health.
 * Armlet of Mordiggian and Soul Ring are commonly built for Skeleton King because Vampiric Aura allows him to heal up quickly after taking damage from these items.
 * Activate Phase Boots and Drum of Endurance at the same time and you'll have enough mobility to chase and kill.
 * Your battle strategy is very simple and straightforward - turn on Armlet of Mordiggian, Phase Boots and any other items you may have, stun the weakest enemy with Hellfire Blast and keep hitting him till he dies. Repeat, if there are other enemy heroes nearby.
 * Grabbing a Force Staff can help make up for Skeleton King's lack of mobility while also providing utility and beneficial stats.
 * Divine Rapier is a very strong item on Skeleton King due to his high dps and great survivability with Reincarnation and Vampiric Aura. If you are losing, picking up this item can easily turn a game around.
 * Refresher Orb is highly recommended. It allows you to potentially proc Reincarnation twice in a fight allowing you to be that much more useful in a team fight.
 * Although picking up the Aegis of the Immortal may seem redundant on Skeleton King, it is recommended if he is his team's main carry. This way, he has 3 lives to expend, and unlike Reincarnation, the Aegis doesn't require mana.
 * It seems counter-intuitive, but you should try to initiate or try to soak all the damage; if you are the last to die, nobody will be able to help you when you proc Reincarnation!
 * It is possible for Skeleton King to kill Roshan at level 1, this is achieved by using Skeleton King's Vampiric Aura in conjunction with Ursa's Fury Swipes. An example of this can be found here.
 * Dagon is highly recommended. It allows you to potentially kill someone from far away, since Skeleton King is a melee hero. Great for finish pesky escape heroes such as Windrunner uses Windrun, etc.