The merethic and early first era. The Nords as a proper race died with the Dragon cult. You can thank Hakon, Gormlaith, and Felldir for that... And I guess Miraak too, traitorous snake he is.

And Valdar.... Tahrodis nikriin!

Now that my quick history lesson is over... onto the build...

I see that you are on Xbox, so this limits the potential unfortunately. The closest you can get to proper Draconic apparel, is the outfit of treacherous Miraak[Dragonborn DLC] The cultist robes are also a possible alternative.

Ancient Nord armor is also an alternative. And my mask goes well with it. Though it is my recommendation that you leave me be. For assualting me is a crime. As an alternative, you can take Otar's mask. He is insane, does not answer my letters for help, and is no longer fit to rule. So feel free to kill him for his mask.

Dragonbone/scale armor is also a suitable alternative, albeit a blasphemous one. But it still honors whatever Dragon you slay at least....

The skills you want to focus on? Seeing as how your clothing options are limited, you may want to go the Battle-mage route. Having a healthy balance of arcane melee might. Conjuration/necromancy shall be your main power. As you bind the Daedra to Alduin's will, and the dead shall rise to Alduin's call by your command. You may also want to have a Dragon Priest dagger as your side-arm, enchanted for your preference. Ancient Nordic swords and axes for serious battle. Be sure to choose an element you wish to focus on. All are acceptable. I personally found great power in shock magic. Though I hear ol' Rahgot was quite the pyromancer. Vokun was proficient in frost magic, which is unsurprising considering his cold, cold heart...

Alteration and illusions are also a plus if you can get a good grasp on them and want to go the more mage route. Or you can go with block and two-handed if you going for a more warrior route, with conjuration as support and destruction for range. Most important? Your tongue. All Priests of Alduin are well-versed in the tongue. Drem Yol Lok. Su'um ahrk morah. Il hin lovaas tinvaak ko Alduin's stahdim sahkren. On Xbox, you can acquire infinite cooldowns by utilizing the "fortifiy restoration glitch." A search through "youtube" should explain it if you do not know it. Others may explain it better than I can. I have no use for it personally, so I lack the details. But I do know that it is possible on consoles.

You posted what you said twice in the post Hev. Perhaps Otar's madness is reaching Valthume?

Maybe... maybe...

Valdar's fault of course. It gets difficult... being locked in here for all these eras...

It will be the route of the battlemage.

What is the race of people that are the blades ancesters?? They use to fight dragons, and they were not in skyim, but came from somewhere else. The killed almost all the dragons in their home land, and followed a few to Skyrim where they gave allegence to someone. I do not know the history all that well, but Nords were not the only ones to fight dragons.

http://www.uesp.net/wiki/Lore:Dragons

Here it is. Had to look it up. Here is the other one. The only magic that Nords used were shouts.

http://www.uesp.net/wiki/Lore:Nord

It was our favored choice indeed. But Nords were no stranger to "practical" magic either. The Priesthood are of course, the most well-known magic practitioners. Our honorable warriors also practiced magic in their own ways. Basic spells perhaps, but notable nonetheless as contrary to the taboo of the Nords today.

Nords don't like magic? The only magic that Nords used was the Thu'um?

I swear, some people need to do some more research on Nordic lore.

And OP, a non-Nord Dragon Priest is about as lore-friendly as an Argonian Thalmor agent.

Nord:

Major: One handed, Destruction, Restoration, Conjuration.

Minor: Up to you. I don't see crafting as something a priest would do but smithing might be necessary to buff defense and weapons. Might do enchanting if you want.

Nahkriin mask (Heavy armor, +50 mag, -20% dest and resto)

Ancient Nord / Ebony Boots

Ancient Nord / Ebony Gloves

Robes of your choice. I'd go Master Robes eventually.

Sword or dagger of your choice. Perhaps Ancient Nord at first, Ebony later. Dragon Priest dagger would be nice but you can't smith it. Perhaps if you go full enchanting it might be nice with some absorb health and magicka.

You absolutely need a staff, peferably the destruction ones. The Dragon Priest Staff would be great if you can get it (pretty hard - strategy and slow time).

Like your thinking, fits perfectly with what I roughly had in mind.