I always hear folks discuss Conan, Elric, Fahfard & Grey Mouser, Throngor...but for me KANE winds up being the #2 influencer when I think of S&S literature.
I spent my flights this week re-reading some classic Kane stories to help fed the creative engine. Kane is an interesting character both smart enough to outwit foes and able to physically crush his foes. Kane is immortal...but can be wounded and potentially killed. The stories are dark and gritty despite the seeming conceit of the hero always surviving.
Who is Kane? From wikipedia:
Little is known about Kane's origins. In the story "Misericorde", he declares to one of his foes that his father's name was Adam and his stepmother's name was Eve, possibly making him the biological son of Adam's first wife Lilith. Like traditional depictions of Cain he is a powerful, left-handed man with red hair, said to have killed (strangled) his brother Abel, and has been cursed by a mad god with an eternal life of wandering. Nevertheless, he is vulnerable to wounds, and it is said that he can be killed "by the violence that he himself created", although his wounds heal at a rapid pace. Kane is portrayed as both an excellent warrior ("I kill things," he tells Elric in "The Gothic Touch". "It's what I was made to do. I'm rather good at it") and an accomplished sorcerer, who spends the millennia wandering from one adventure into the next. Also like the Biblical Cain, Kane is marked as a killer; those who meet the gaze of his icy blue eyes cannot maintain contact for long, for they give away Kane's true nature as a butcher of men.
He is often compared to Conan the Barbarian, but Kane is quite different in that he is a devious character with a more somber and reflective outlook on life than Conan and has none of the latter's dislike of sorcery. His creator described him as a character "who could master any situation intellectually, or rip heads off if push came to shove". Some commentators have argued that the fantasy protagonist that Kane has most in common with is Michael Moorcock's Elric, but Wagner was also inspired by Melmoth the Wanderer. Kane is unconcerned with common morality, since no human relationship can ever last more than a small fraction of his lifetime (although the daughter he fathered in "Raven's Eyrie" turns up as an adult in the modern-day "At First Just Ghostly"); and he frequently ends up on the wrong side in the conflicts in which he involves himself, often to his own detriment. A common theme running through all Kane stories is the hero's weariness with his own immortality and his attempts to give his existence meaning.