Hey guy this is my first build so I have no idea how this will go but you came here for an awesome build so here we go.
Out of the 14 dragon Preists at ravakheim you being the 14th one. The most powerful one, The Warlord, you were considered the unstoppable one. The other dragon priests feared you so much that they wanted to get rid of you. What they didn’t know was that you had half of Alduins power. Near the beginning of the dragon war when all was falling apart you made 2 spells (that were later lost to time). The first one abjuration bolt could be learned from the warlord elder scroll, the ancient nords of the time somehow learned of the words of power for the bolt made scrolls. The 2nd you had cast on you mask that if you were stripped of it and put in a crypt in a sleeping state till Alduins return. When the mask is taken off it would activate the spell that would curse all the other dragon priests with undeath. The time came when all the other 13 priests paralyzed you with a spell that they had to combine their magic to do. During the night the took your paralyzed body to brominjaar sanctuary and stripped you of all your gear. The mask they put in the shrine. The robes, gauntlets, boots, and your body they took back to Ravakheim. They didn’t know of the spell you put on your mask making them undieing. They then took you to a barrow in the hills by dark water crossing and buried you there. 200 years later you woke up trying to remember what happened. As soon as you stepped out of the barrow it disappeared into dust. It wasn’t until at the crossing when you realized that you had turned into a khajiit and remembered all that had happened. You were then captured by thalmor when they were combing in looking for more Stormcloaks as they had ulfric already and some others. When you reach Helgen this is when your story begins......
Kill the dragon priests in Skyrim, and solstheim as 5 are there
Go back in the past and get your gear back
Craft your dagger of power( drain health and fire)
Then kill Alduin to absorb the rest of his power
College of winter hold
Side with the dragons not alduin
Blades spare parthurmaux
Join dark brotherhood
* = mods
Konahriks ring (silver ruby ring)(fortify destruction)
Dragon priest amulet*
Konahriks fang* (fire and drain health)(needs mage Charlie mod for power up potion)
Credit to Nozi87 for the video