Gold Knight

The Gold Knight is a main boss and NPC in Hollow Knight: Lost Souls. He is first found in The Ruins alongside Hornet. Once you enter the screen with them inside, Hornet uses her silk and grapples away, leaving Gold Knight to deal with the threat. Defeating Gold Knight will unlock dialogue with him. He will allow access to the rest of the temple, unlocking the Gold Slash spell. He will remain as a merchant in this spot for the rest of the game, allowing him to be hired as a mercenary to help you the next time you fight a boss. Note that he will NOT appear during Gold Knight and Shade Keeper bosses.

After the defeat of the Unified Traitor Lord, he will move to The Hive in which he can be seen talking to a Hive Knight. Approaching him will cause the Hive Knight to run away, and speaking with him will grant you the Hiveblood charm. He will return to the Temple after this encounter.