The Spell Sword [SEP] series
The Spell Sword
The Spell Sword is a sword and planet novel by American writer Marion Zimmer Bradley, part of the Darkover series. The book was co-authored by Paul Edwin Zimmer, Bradley's brother, though he was not credited. "The Spell Sword" was first published in paperback by DAW in 1974 and has been republished several times.
This book is the first in a trilogy within the Darkover series dealing with the evolution of Towers and Keepers. The sequels are" The Forbidden Tower" (1977
, who sought the Pasa sword. Loruan sacrificed himself using a forbidden spell in order for Rey and Shyao to escape with the Pasa sword. 
Summary.
Six years later, at the start of the series he travels with Shyao Lin. Though Shyao denies any feelings for Rey and claims to be his 'older sister', Rey begins to feel something for her, quite obviously. He wields an immensely powerful sword, The Pasa sword, with the power to consume demons blood and souls to augments its powers.