Magister Ladd:
The final ingredient, Blood Fire, can be obtained by defeating the Bloody Guardian at the Watcher's Tomb.
Once you obtain Blood Fire, you must use the ingredient mixing urn in the basement of the Ivory Tower to create Mimir's Elixir. Mix Pure Silver and True Gold, then use the Blood Fire as the catalyst. Then, set the temperature to phoenix...
Once you complete creating Mimir's Elixir, please bring it back to me. I will tell you how to use it!