Seeing the title I had the immediate association with Legacy of Kain series, and I see I wasn't that far in my judgment - the internet claims that the main character is also heavily inspired by Elric of Melniboné.
I will most certainly check it out in the near future.
Kane is an immortal and, not a traditional hero, he more of antihero type character. He not a nice person at all but , he an interesting character. This is a dark fantasy series comprised of 5 books
1. Bloodstone
2. Darkness Weaves
3. Dark Crusade
4. Death Angels Shadow
5. Night Winds
The series has both gothic and lovocratainj elements . Thought Bloodstone is listed as book 2 , Its book you should start with. It interesting that you mention Elric of Melnibone . The last Kane story that wager wrote
A Gothic Touch It can be found in the Anthology
Elric Tales of the White Wolf In this story Kane meet Elric of Melinibone and Moon Glum. it seem he has need of Stormbringer
Wagner also wrote Conan the road Of Kings an excellent Conan pastiche and
Bran Mak Morn The Legion from the Shadow. A pastiche of another Howard character Bran man Morn and this too is excellent book
Killer which he court with David drake
In a Lonely Place is an anthology of his best horror stories
Echos of Valor I, II and III. in this trolley anthology Wager presents heroic fantasy stories well known and less known .
Echos of Valor III in particular contain s 3 excellent stories by a man named Nictzen Dyhalis . who is very little known given that he only wrote 11 fantasy stories in all.
Unrelated but you find this of interest.
The Star Rover by Jack London This book is his only fantasy novel , It largely unknown aan unlike all his other novels . Ks about straitjacketed DeathRow in mate who discover via transcendental mediation that he can not only lever his body but can astral project himself into his past lives at will. This is book. epic in scope scale , takes you across time ,space and history . Its great book and can be found online via Project Gutenberg .