Enter the Cathedral Level 3. The game saves a checkpoint just as you go in. As you proceed, the objective "Descend through the Cathedral" completes. You soon come across a chamber with Dark Cultists in it, surrounding a warrior. One of the Cultists shouts to maintain the incantations, he will soon turn. It appears they are conducting some sort of evil experiments on the warrior.  Your task is to give aid to the warrior.



Kill all the Dark Cultists surrounding him, to break their spell. After you kill a few of them, the warrior breaks free. Talk to him. You ask him who he is, he tells you that you will know soon enough. He wants you to help him find his gear, and he will reward you well. Your next priority is to find the warrior's stolen items. When you talk to the warrior, you discover that he is also seeking to challenge the Skeleton King.

Proceed deeper in the cathedral. There are Skeletons here, as well as Servants of Jordar. The warrior will let you know when you get close to his weapons, and then he will go and take them and equip them. He tells you that his is Kormac, warrior of the templar order. If it is the Skeleton King you seek, then you will have to fight your way past Jondar. There is no reason we should hunt alone.

You now need to find and kill Jondar. Kormac becomes your follower. There will be another boss here, Fausto Devilkin (Teleporter). Fight him alongside with Kormac. Then continue along the corridors, fighting more Skeletons, Servants of Jondar, and Necromatic Minions. Soon you descent through some stairs, and fight Jondar, a purple boss (Necromancer Betrayer). Jondar summons skeletons to fight you, as well as shooting poison projectiles at you. You should focus on killing Jondar, and let the Templar deal with the summoned skeletons.

Once you defeat Jondar, the Templar thanks you for your aid and tells you that he will go with you on your hunt for the Skeleton King. But there is one condition. If you find the Sacred Tomes of the Templar's order, they are his. You agree, which completes an objective to join the templar. You get a choice now:

Templar
The Templar is a fierce melee warrior who wields a shield and one-handed melee weapons.
Do you want the Templar to join you?
If not, they will travel to town and you can return there to get them at any time
yes/no

Unless you are grouped with other players, you should choose yes to have Kormac join you, as this will make your next battles easier. You can also choose a skill for him, and it is recommended you choose the heal skill, which you will most likely need in the upcoming battles. You can left click on his icon to access the Follower menu or right click to talk to your follower. Once you are ready, continue through the Cathedral.