Sir Valorcrest

Spawns with 0-4 Vampires, you will notice FAR more vampires close to the stairs than usual at the Vampire cave when this creature spawns. You can use a blessed wooden stake on his corpse in order to get Vampire Dust.

Summon as many Vampires as he can and tries to kill his enemy with strong melee attacks and makes you drunk. He fights to the death and doesn't run away in low health - This could be because of the fact that he seems to be a Knight Vampire due to his high melee damage, name, and honorable fighting style (Fights to the death).

Knights: It IS possible to solo this creature for a knight of level 80+ (it's still not recommended, however) using defensive fighting, Great Health Potions and Exori, just take around 150-200 Great Health Potion and about 50-80 Mana Potions to do this, because killing him is expensive so do this only if you REALLY want to kill him, in order to do this lure him to the stairs, then make sure he's at melee range and attack him with your best weapon and use Exori as often as you can to deal damage to him and get rid of the Vampires surrounding you, as damage will decrease once you kill the Vampires that regularly spawn in the cave as you will only have to fight his summons. It's best to make them run away, as they won't respawn and you can focus on fighting Sir Valorcrest, just keep using Great Health Potions as often as you can, whether you need them or not, as a strong combo can give you a free trip to the Temple. If your health goes below 200 it's recommended to go upstairs to heal and then go back.
Mages should have a blocker and shoot with fire spells, but other elements work too.
Paladins: Same strategy as mage, blocker and shoot with bolts/Enchanted Spears while using Divine Missile.
Higher Level Knight can block it (100+) while a Paladin/Mage quickly kill it.