MTG Salvation

Quote from ahoy

Don't look for cards that trigger on gaining life, that's small time and small effects(usually). Look for cards that let you spend that extra life.

With a few exceptions I agree 100% with this.

It depends on how you define synergy. These are all cards that either directly interact with Oloro, are improved by Oloro or combine with other cards that have synergy with Oloro.

• Exquisite Blood
  
• Vizkopa Guildmage
  
• Greed
  
• Phyrexian Arena
  
• Necropotence
  
• Drogskol Reaver
  
• Bloodgift Demon
  
• Unfulfilled Desires
  
• Paradox Haze
  
• Felidar sovereign
  
• Test of Endurance
  
• Serra Avatar
  
• Phyrexian Processor
  
• Minion of the Wastes
  
• Pristine Talisman
  
• Well of Lost Dreams