Requirements: 60 Crafting is required to make the Crystal Key once the crystals have been obtained.
With this Crystal Key you can:
- Access the Slayer Master located in Catherby.
- Use a shortcut that goes directly to the Greater Demons, located just next to the entered Taverly Dungeon.
- You can then also enter the shortcut chamber located a lil further in the dungeon.
The Crystal Key can be crafted by combining two different crystals with each other. They are dropped by two separate monsters located in the Taverly Dungeon. The combat 82 Lesser Demon drops one of the crystals while the other one is dropped by the combat 97 Skeletal Hellhound.
((Sidenote: The monsters can only be killed, while on the related slayer task.))
Thank you X minh X for tutoring me on the topic.