I have beaten 2 wings Blackwing Lair. I will guide you with real-time strategies and personal experiences with clearing them with with most of my basic, Nax and Blackrock wing cards as possible. I walk the talk and also aim is to get more Legendary cards without purchase.
Hero Power (Normal) - The Rookery - Give all Corrupted Eggs +1 Health, then summon one. (1 mana)
Hero Power (Heroic) - The Rookery - Give all Corrupted Eggs +1 Health, then summon one. (0 mana)
I used the basic face rogue deck from Sottle at Icy-Veins with card swaps to defeat Razorgore. You'll need the tempo e.g. Backstab, Shiv, Fan of Knives, Assassinate, Deadly Poison, Sap to clear the Corrupted Eggs before they get bigger and hatch. Combine this with a good mana curve of cheap, effective/Deathrattle minions, weapons and finally expensive efficient minions like Chillwind Yeti, Loatheb, Sludge Belcher and Boulderfist Ogre to defeat Razorgore. RIP Razorgore.