He is immune to paralysis as well as the Bend Will shout.
Furthermore, he somehow has the ability to use dragon shouts, and will use Unrelenting Force and Disarm. He can also cast several spells, including a 15 second paralyze spell, Close Wounds, Command Daedra, Conjure Storm Atronach, Frost Cloak, and Ironflesh. His sword has a life- stealing effect and his bow is enchanted with frost. His enchanted armor also gives him 50% resistance to fire, frost, and shock magic, making him difficult to hurt with magic. He has the Reflect Blows perk from the Heavy Armor Tree, allowing him to reflect 10% melee damage back at you. The Ebony Warrior is a formidable adversary. You can even bring a dragon to the fight by discovering the location, finding a dragon (Like Odahviing at the Throat of the World) and fast traveling back to Last Vigil to land. Have your strongest weapons and armor, enchant and improve everything, bring plenty of potions, and bring a friend. This fight may very well be the hardest you will face in your adventures, so prepare accordingly.