Defeat the Keeper after changed his magic school to Fire. Lords of the Fallen Ancient Labyrinth DLC Played with Fire trophy.
How to manipulate Keeper's magic school: https://youtu.be/0cylbcazh7E
With the different magic school different weapon will drop.
Lithic Rising (Fist) - Requires Strength 32 - Lightning magic school
Scalpel (Polesword) - Requires Agility 28 - Ice magic school
Between (Greataxe) - Requires Faith 26 - Fire magic school.
My guess is that stronger the magic school - better the weapon and less restrictive is the requirement to use this weapon. Now I should upgrade Faith to the level 26 and use GreatAxe Between to defeat the Judge (final Boss in the Lords of the Fallen).

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