Once you have a all 4 pieces (aban-bothar-chi-dom) of the pattern, combine them to make a complete pattern (go not use novictum on it, this part requires that you only complete the patern) then head back and show it the Diviner. Once he has seen this you will now be asked to retrieve information from a Diviner.
After the quest is updated, you can then finish the process and make the pattern into a Novictalized Notum Crystal. Check our Pocket Boss Guide to learn how to complete the pattern.
Take the crystal to a 160+ incarnator and activate the crystal (there is a lvl 170 incarnator northeast and a lvl 190 incarnator northwest from Adonis City South).
When the demon spawns he cannot be attacked for 6 minutes (this is because the omni version requires for players to talk to him), once this time runs out kill him and loot the blueprint of the Diviner Gil Kald-Thar pattern from it's corpse.
Make this pattern into a Novictalized Notum Crystal (same process as with the previous complete pattern). You already know where you can spawn the Diviner. Once he appears you have 6 minutes to talk to him, during that time he cannot be attacked.
After some talking you will get "Record of Lost Diviner", bring it back to Diviner Gil Yeol-Ulma and you will be rewarded with your sanctuary key!