Summary: Gnaag is the Darklord who manages to rule over the other Darklords by playing them against each other and through his strength and genius. He then makes your life as Lone Wolf absolute hell. All you want to do is recover some lorestones, but Gnaag brings the might of the Darklands against you in order to thwart you. Eventually, you do recover the Lorestones and get sick of Gnaag picking on you so you go to the capital city of the Darklands, Helgedad, slay Gnaag and blow up the city. That will teach him.
Prominence: You don't see him for very long at all, but for several books, Gnaag is working behind the scenes on a relentless quest for absolute power. It is his idea to hunt for the Lorestones of Nyxator in order to stop Lone Wolf obtaining his Grand Mastership. So most of your tribulations for seven books are down to him 11/10.
Hardness: Gnaag has a combat skill of 50 and an endurance of 70, which, for a magnakai is a huge challenge. He can also use all kinds of crazy magic and god knows what. He can only be harmed by the Sommerswerd or the weapons of the Darklords. However, if you have the Sommerswerd, you can blast him into nothingness without a fight. 9/10
Ambition: He wants to conquer all of Magnamund and gets worryingly close. 10/10
Style: I expected all of the Darklords to be clad in black plate armour. Haakon is closer to my idea of a Darklord. However, Gnaag really breaks the mold. He's a giant fly. I would never have expected a giant fly-man to wield almost supreme power over Magnamund. His image is quite original but he's a bit dry when it comes to conversation. 7/10.
Diabolical genius: This guy really has some great ideas. Once he obtains power over the darklords by playing them against each other, he swiftly raises a huge army and launches a fast and devastating invasion against his enemies. His crowning achievement, however, is placing the last Lorestones of Nyxator, artefacts you must obtain, over a shadow gate into another dimension and making you fall into it. That comes as close as anyone gets to killing you as it keeps you out of the picture for eight years. As well as being your nemesis, he also managed to keep the other treacherous and cruel Darklords under his control. This guy is really good with time management. 10/10
Total score: Gnaag has all of the brilliant characteristics of many villains and manages to sustain this over several books. He is definitely someone you don't want to mess with. 47/50