First off, let me explain the basics of the Voidwalker tank spec to those who are unfamiliar with this new build since patch 3.0.2.
Talent Calculator - World of Warcraft
This spec allows one to basically use the Voidwalker as a true tank, and with the new pet buffs, one is able to keep it alive through Health Funnel, and is able to keep their health topped off at all times, using Siphon Life on the boss and the new version of Fel Armor.
This guide was initially inspired by this Onyxia soloing thread: http://www.mmowned.com/forums/wow-gu...ng-onyxia.html
Now on to the actual guide:
First, you'll want to position yourself like so, ensure your pet is on STAY:
Upon killing his priest minion which actually starts the fight, you'll want to taunt Bloodlord Mandokir ONLY with your pet. Toss a Siphon Life on the raptor and run up the pyramid, jumping off onto this ledge:
Throw a Siphon Life on Bloodlord and continue to heal your pet with Health Funnel until the fight resets. As soon as you see Bloodlord begin to reset, make your pet attack him. This will force the raptor to despawn from the fight, leaving Bloodlord alone against you and your pet.
You may then proceed to DPS Bloodlord and heal your pet until he of course dies.
Screen shots of me soloing (please note the mage in my party is only there to allow me to be in the raid instance, as you can see via my map, there is nobody else in the instance.):
Video coming upon next reset.
Due to a common misconception, I've decided to include this little tidbit: Bloodlord's threatening gaze will NOT affect you in any way, shape, or form. You are free to ignore it throughout the entire fight.