Nightblade, illusion, destruction, and sneak
Mostly a mage, can turn all enemies against each other and blast whoever is remaining. Or because of sneak perks and a few measly 1 handed perks, I can invisible and go slit throats. If they have too much hp for a stealth death I’ll calm them instantly and do it again. Dragons and bosses immune to illusion or stealth? I’ll blast them like the destruction mage I am. I took up alchemy as a craft and made fortify destruction potions and magicka potions that make me stronger than even a pure mage, despite having to carry sneak and one handed perks.
It was the most fun I’ve I had on a playthrough. The only disappointment was the lack of robes available. You have to wear the archmage robes forever