How do I find the Ebony Warrior?

How do I find the Ebony Warrior in Skyrim? I have been searching for him for ages, and a friend of mine said he met him at level 20 on the Skyrim Legendary Edition. I still don't know where he is, and my friend said he normally finds him in Windhelm. Is this true, or is he a random occurrence?

I'm playing on the Xbox 360.

Solution 1:

The Ebony Warrior will only appear once you have reached level 80. Once you're level 80, he will approach you if you're in any major city, not just Windhelm.

Upon reaching level 80 a mysterious warrior wearing a full suit of ebony armor [The Ebony Warrior] will approach you in any major city and challenge you to a duel at his Last Vigil. The quest will then update to give his location, a camp northeast of Fort Greenwall. The Ebony Warrior will not attack you when approached, and will not speak. He will simply stand, brandishing his sword as a clear invitation. You must initiate the attack for the battle to begin. Make sure that you are prepared for one serious fight. It is advised to wear the strongest armor you can get and have plenty of potions at the ready. You may want to bring a follower as well.

Source: The Ebony Warrior, UESP wiki