Each week Dominic Hobbs brings you Blood Pact. A journey into the shadowed side of your magical being, taking in all the sights from the dark heart to the withered soul. Where we learn the true price of power.

In the last 'Meet the minions' we looked at how to control your summoned demon and had a good look at the imp. This time we are showcasing the voidwalker and learning what threat is all about. Knowing how to make sure the enemy leaves you alone and hits someone (or something) else is a key ability in the game and the voidwalker is the ideal tool for learning it.

Your voidwalker is a tank. You usher him to the fore and while he keeps your target busy, you destroy them with shadow and flame. I tend to think that the image of a voidwalker is pretty bland, the other demons are much more evocative. Despite this the voidwalker is probably the most evil of minions to use on your enemies. It will reach into their minds and cause such anguish that they will desperately try to beat away this monster. This affords the warlock all the time he needs to safely curse and corrupt their bodies with exquisite slowness and care.

You first gain the ability to summon your voidwalker from a quest you can pick up at level ten. The quest giver will be in your home city (unless you're a gnome in which case they're in Stormwind) and will tell you how to learn the spell. The basic form is 'go get this thing,' 'use thing to summon a voidwalker,' 'defeat voidwalker,' 'win.' get this done and you have your very own blue, braceleted bully-boy -- so now you're gonna need to know all about threat.

Threat is a measure of how much a mob wants to attack something, generally you increase your threat on a mob by damaging it. The more threat you have the more they are inclined to attacking you. This is different from aggro which is a binary thing -- you either have it or you don't. You get aggro by engaging a mob (attacking or walking too close to them) or, if someone else has a mob's aggro already, you can take it off them by raising your threat enough so that the mob wants to hit you more then them. This is important stuff for fighting in a group but also fighting with your voidwalker.

For a long time the only way to measure your threat was through addons like KTM and Omen, now there is an inbuilt threat meter. Personally I still prefer Omen as it lets me know the threat levels of my whole group and gives a better idea of how much threat my tank is generating. Whatever tool you use it is important to keep your threat low enough that the tank is the one getting hit and not you. For the default UI, reaching 100% means you will become the mob's target (gain aggro). For Omen 100% of the current target's threat will not mean you take aggro, you need 110% in melee range or 130% if outside it (as you normally will be).

When you first get your voidwalker he will only have the one ability, that's Torment. This will raise his threat level without doing damage. He does do some damage by hitting the mob but not very much, he gets his threat through casting Torment. Once he has started tormenting the mob you can start attacking it. It is worth starting off slowly so your voidy has chance to build up some threat -- remember, you want to keep under the voidwalker's threat level so he keeps aggro. Curse of Agony is a good way to start as it does small amounts of damage to begin with.

Take your voidwalker out and practice, it doesn't matter what mob you go for but find one that is about your level and is alone (we'll come to groups in a moment). Start to get a feel for how much threat each of your spells generate and how much damage you can do without taking aggro from your void. Try leaving him attacking one for a while without doing damage and then do a load all at once. Try seeing what you have to do to take aggro from him. All of this will give you an understanding of how to do the most damage in the least time without being the one getting hit.

If you send your void into a group of two or more mobs then he will gain aggro from them all because he's the first enemy they see; they will all start to attack him. He'll be Tormenting one of them and building up a nice pile of threat with that mob. The other mob (lets assume there are just two) will have his aggro on the voidwalker but won't have any threat level for it. If you do any damage to this mob you will very quickly gain the aggro and he'll come running for you. The same is true if you heal yourself or the voidwalker.

You need to decide if you want to let your voidwalker keep one mob (or more) busy while you kill another one quickly, or have your voidwalker hold onto the aggro of all the mobs while you kill them all slowly. Either strategy is viable but work differently. To get your void to keep aggro on all the mobs you need to make sure he attacks them all by changing his target often and not doing so much damage to any of them that they turn on you. This can be tricky but is a skill worth learning. Being able to apply DoTs such as CoA, Corruption and Immolate make it much easier to spread a little damage across a lot of targets at once. Curse of Weakness can also help by reducing the damage the void takes and therefore any healing he might need.

As you and your voidwalker grow up he will learn new abilities. Suffering works in a similar way to Torment except it gains him more threat and does so with every mob within 10 yards of him. However, he can only cast it every 2 minutes as opposed to every 5 seconds for Torment, so use it at the right time.

Consume Shadows can only be used outside of combat and you have to tell him to do it. This will heal him up and mean that you (and close party members) can better see stealthed enemies. This can be handy in PvP but the voidwalker still isn't much of a PvP minion.

Sacrifice originally killed the voidwalker for a personal shield; this was changed to only take a portion of the voidwalker's health. What you get is a nice bubble around you that will absorb a load of damage and stop your spells being slowed down. This is great if you have your voidwalker tanking something and then you accidentally take aggro, it lets you either quickly finish off the mob, or heal up the void while he torments the mob back off you.

The voidwalker is seen as the ideal tool for levelling with good reason. Once you reach level 14 you have Health Funnel, Drain Life and of course your voidwalker. This turns you and your minion into a rounded group. You cover off the tanking, the healing and the damage dealing. If you chose the right talent build you can make your voidwalker extremely tough and effective -- so much so that many group quests that call for you to find a dedicated tanking player can be soloed by a warlock with a voidwalker.

Don't be fooled into thinking that your voidwalker is as good as a player tank though. A player would have to be very bad to not generate more threat than your voidwalker. While he has high armor and deep health pool he can't dodge, parry or block attacks. Avoidance does mitigate most AoE damage but you don't get that until level 60. You might have heard of voidwalkers tanking raid bosses and this is true -- I used my void to tank Sartharion with 2 and 3 drakes -- but this fight is the exception. The only reason this worked is because Sarth does a lot of AoE damage (Flame Breath) and the raid doesn't attack him first, they are busy with the drakes. This means that damage incoming is managable and the void only needs to out-threat his healers.

Blizzard weren't happy with this use of a voidwalker and so they implemented nerfs to both his health pool and threat generation which made void-tanking of Sartharion much harder. While I agree that void tanking may put a tank out of a raid position I don't think the health/threat nerf was the right way to resolve the issue. The health nerf meant that the void now has the same health as the felguard and even succubus. This means that if you can summon a felguard then you have no good reason to summon a voidwalker ever again, he'll do a better job in almost every case (except the Sacrifice bubble). I would rather they had made Sarth's breath ignore Avoidance or the like. Threat generation did need a nerf (at one stage they could take aggro from a good tank that was really trying) but again, I feel this was too harsh and now the void doesn't generate all that much threat so you have to be very careful with your damage.

All that said, the voidwalker is an excellent minion for levelling and soloing. Along with the imp the voidwalker is one of the strongest symbols of a warlock. He's instantly recognisable immensely useful. He's also the hottest topic for discussions about having new demon models in future expansions. The Burning Crusade in particular saw a lot of new voidwalker skins enter the game and a lot of locks would like to see these make it to the summoned voids. I've not heard anything about this for Cataclysm but I wouldn't be surprised if it crept in there.

Blood Pact is a weekly column detailing DoTs, demons, and all the dastardly deeds done by Warlocks. If you're curious about what's new with Locks since the last patch, check out the Patch 3.2 Warlock Guide or find out what's upcoming in Cataclysm from the BlizzCon 2009: Class Discussion Panel.

This article was originally published on WoW Insider.