Aggressive or defensive lane support. Right-click carry buff-er. Position 5.

Ogre Magi is usually picked for a tankier support that can boost the damage output of your right click carries. He is a pretty flexible pick, most teams can take advantage of a stun/nuke and slow in some manner, and chances are most drafts will have at least 1 right click carry which can use Bloodlust. To get the most out of Bloodlust, pick Ogre into a team with carries with high right click damage but low attack speed such as Outworld Devourer, Drow Ranger, Silencer, Alchemist, Faceless Void etc. As a standard rule: the more on-hit crits, bashes, or orb effects the better. But even if you don't pick Ogre into an ideal team, he can usually perform pretty well in most circumstances, because he's still a big, high health regen support with decent crowd control.

Rod of Atos > Ignite > Fireblast
Unrefined Fireblast can be added on to the end of this combo if you decide to purchase Aghanim's Sceptre.

• Tanky - Can soak damage in lane in order to support a hero with a weaker laning phase, such as Spectre.
  
• Buffs Teammates - Stays relevant even in the late game, because stuns and slows are always useful, and Bloodlust can massively increase the damage output of your carry, giving your team the edge over the enemy.
  
• Cast Range - Built the right way, Ogre's cast range is very large, and can offer a lot of control from a long distance
  
  
  Weaknesses:
• Lack of Escape - Ogre struggles to get out of gank attempts and losing teamfights. Force Staff and self-cast bloodlust help, but only a little.
  
• Single-Target - With the exception of a modest AoE on Ignite after Multicast is levelled, all Ogre's abilities are single target, meaning he struggles to control more than 2 enemies at once.
  
  
  Friends:
• Outworld Devourer - OD hits veryy hard, and builds almost all his items to increase his Intelligence or Attack Speed. Ogre saves OD having to buy Attack Speed, so he needs less items and therefore gold to carry.
  
• Silencer - Similiar to OD, Silencer's glaives allow him to hit hard. Bloodlust increases attack speed to put that damage in faster. Ogre is also a good ganking partner for him, helping him steal Intelligence early in the game.
  
• Alchemist - Also countered by Ogre, Alchemist has a terrible base attack time, taking Bloodlust at level 2 can help him get last hits in lane and jump start his farm.
  
• Faceless Void / Spirit Breaker / Troll Warlord - Bloodlust means more attacks, more chance to bash, and keep enemies permanently bashed, and unable to fight back. Spirit Breaker's movement speed is also increased by Bloodlust so his charge does more damage.
  
  
  Foes:
• Phantom Lancer - Ogre can't really control all the illusions in a teamfight, and Force Staff won't save you from him as PL can always Phantom Rush forward.
  
• Centaur Warrunner - Bloodlusting teammates just increases the number of times Return will proc on them, if they attack Centaur. Stampede means Ignite has no slowing effect, and generally Centaur is tankier than you.
  
• Meepo - Ogre can't control all the meepos well, and struggles to get away, as Meepo can always poof back up to you