Radahn's Great Rune is a Great Rune in Elden ring
Description
A Great Rune of the shardbearer Radahn.
Its blessing raises maximum HP, FP, and Stamina.
Radahn was amongst the children of Rennala and Radagon who
became demigod stepchildren after Radagon's union with Queen Marika.
The Great Rune burns, to resist the encroachment of scarlet
rot.
Effect
Raises raises maximum HP, FP, and Stamina
Acquisition
Upon the defeat of General Radahn
Notes
To use a Great Rune it must brought to the appropriate Divine Tower (In this case that would be the Divine Tower of Caclid)