Keys to either Temple of Shadows or Desire Cavern are needed in order to have access to higher level floors, most importantly to bosses otherwise inaccessible without the keys. In order to make the keys of either Temple of Shadows or Desire Cavern, you must have at least level 1 karma of the corresponding key you are trying to make. For example, you need to have level 1 or higher Varlok karma (killing undeads) in order to make Temple of Shadows Keys. Also, you cannot make one of the keys if you already have a key of the opposite side (ie. You cannot make the Desire Cavern Key if you already have a Temple of Shadows Key). Therefore, if you made a key for one side and decide you want to make a key for the other side, you must delete the key that you already have in your inventory in order to do so.
Temple of Shadows Keys
Once you have level 1 Varlok karma, Keys to 2nd and 3rd floor of Temple of Shadows are relatively easier to make than the Desire Cavern Key.
-In order to make the Key to 2nd Floor of Temple of Shadows, you need:
1,000 Fragments of Soul Stone +
Head of Chaos =
Key to 2nd Floor of Temple of Shadows
-Key to 3rd Floor of Temple of Shadows is made the same way, you need:
1,000 Fragments of Soul Stone +
Head of Death (only need one, choose your preferred color) =
Key to 3rd Floor of Temple of Shadows
Fragments of Soul Stone can be obtained by killing undead monsters in Temple of Shadows or SOE. The Heads of Chaos/Death can be obtained by killing the respective bosses for them. Once you have the required materials, head to Varlok's Laboratory in Desire Cavern and speak with the NPC "Incarnation of Varlok" to make the key.
Desire Cavern Key
Once you have level 1 Yahee karma, you can start on collecting the seals needed for the key. In order to make the key you need to collect a total of 810 seals from the rooms (Air/Fire/Water/Earth Rooms) within Desire Cavern. Collecting the seals require a certain order and cannot be all from one room. The order to collect the seals is:
10 seals from one room,
100 seals from the next room,
200 seals from another room, and
500 seals from the last room.
You can choose which room to collect in first so you can leave the easiest room last.
-The suggested route for melee/ranged characters is to go for 10 Air Seals, then 100 Fire Seals, then 200 Water Seals, and finally 500 Earth Seals. The reason for this order is because Air Room monsters hit the hardest while Earth room is the easiest.
-The suggested route for mage is to go for 10 Water Seals, then 100 Air Seals, then 200 Fire Seals, and finally 500 Earth Seals. The reason for this order is because mages cannot summon in the Water Room, therefore, making it the hardest room for them.
When you go to the first room and touch the Dimension Door, it will tell you something is protruding through the door. If you are sure that you want to hunt that room for seals first, then go ahead and remove the protruding part:
You will receive the Pass of Air/Fire/Water/Earth.
Once you take the Pass, you cannot enter the other rooms in Desire Cavern without giving up any seals that you may have. Take the Pass and collect 10 seals from the first room.
Once you have 10 seals from the first room, return to the Dimension Door and touch it again. You will then receive Air/Fire/Water/Earth Commander.
Once you have obtained the Commander, you may now move on to the next room of your choice. Repeat the process of taking the Pass, collecting the seals (100/200/500), and receiving the Commander in the next three rooms.
After you have obtained all four Commanders, go to Temple of Shadows 1f and go to Yahee's Laboratory. Find him walking around and speak with him. He will give you an option to make Ruler of the Elements, which is the Desire Cavern Key.
Click on that and receive the Elemental Commander:
An important fact in hunting for karma is that if you kill a monster from your own faction (ie. you have Varlok karma and kill demons), you will lose more than the original karma value of the monster. Killing a monster from your own faction will reduce your karma by the monster's karma value multiplied by four. Therefore, if you have Varlok karma and kill a Shiboin of Air/Fire/Water/Earth, then you will lose 6 x 4 = 24 karma. This knowledge is useful if you decide to switch sides one day and hunt for the opposite karma. Therefore, if you have level 2 Varlok karma and decided to make a Desire Cavern Key, the process to reverse/erase your karma is much less tedious.
Trading in Fragments for Karma
Reversing/erasing karma by trading in fragments will still net you 100 karma, not 100 x 4 karma. Speak with the NPC, Consul, to trade in Fragments of Soul/Blood Stones on the 1st floor of Desire Cavern and Temple of Shadows, respectively.