The Orbital Sword: The Green Knight (Space Lore Book 1) by Chris Dietzel

Near the border between two kingdoms, a vessel full of innocent passengers is destroyed. While the extent of the impending retaliation is unknown, its inevitability is not. Galactic war is approaching. In a seedy bar in a distant corner of the solar system, a knight clad entirely in green armor puts forth a grisly challenge. The only person to accept the knight’s game is a woman who spends her time drinking and thieving. These two acts, occurring in different parts of the galaxy, both lead to the same spot: the planet that will soon fall under attack. Welcome to Space Lore, where Arthurian legend meets Star Wars. Epic space fantasy will never be the same.