Lone Wolf Series Books 6 - 12 Collection Set by Joe Dever:

The Kingdoms of Terror:
YOU are Kai Master Lone Wolf - last of the Kai Lords of Sommerlund, sole survivor of a massacre by the Darklords of Helgedad. You discovered the lost Sommlending treasure, The Book of the Magnakai, containing the wisdom and Disciplines of the Kai lords.

Castle Death:
You are the warrior, Lone Wolf, last of the Kai Masters of Sommerlund and sole survivor of the massacre that destroyed your kinsmen during a bitter war with your age-old enemies the Darklords of Helgedad.

The Jungle of Horrors:
In the Jungle of Horrors, you must face these terrifying dangers while avoiding the machinations of Warlord Zagron and other powerful foes. Time works against you as your ancient enemies, the Darklords of Helgedad, seek an end to their civil war.

The Cauldron of Fear:
In this book, your quest takes you to the Republic of Anari and into the lightless depths beneath its capital city. With the shadow of war ever-present, you must face the dangers of an ancient metropolis and recover the Lorestone of Tahou.

The Dungeons of Torgar:
In THE DUNGEONS OF TORGAR, you must travel to the city of Eru, where Prince Graygor will help you reach the infernal Drakkarim stronghold where the Lorestones reside.

The Prisoners of Time:
Archlord Gnaag has cast you into the twilight realm of the Daziarn, hoping to banish you forever while the armies of the Darklands continue their conquest of Magnamund!

The Masters of Darkness:
Archlord Gnaag awaits you in the Black City, and your battle against this overlord of evil will determine the fate of your world!