So I have a Wood elf, thief birthsign, and thief class.
What is the best way to get the nighteye spells without doing those boring mage quests? And I want to be a pure thief guild member
Nor am I going to join the dark brotherhood for the dude inside selling potions, first because assassination in oblivion is plain and other games even assassin's creed does it better, second because I already killed lucien.

thanks

Various mage's guild NPCs sell Nighteye, and you don't have to join the Guild to buy them. I think the also might sell it.

Mystic Emporium Sells Night Eye

You could become a vampire which gives u a good night eye spell, or u could get fin gleam.

Easiest way to get night eye is to deliver the amulet, go to Kvatch, retrieve the sigil stone from the Gate (save/reload until you get a sigil stone with night eye on it), then use it to enchant a ring or amulet.

The spell is short term and a magicka hog so it won't do your magicka challenged character much good without access to an enchanting altar. Also casting any spell tends to blow your cover. If you're on a PC you can download a mod that provides enchanting/spellmaking altars without needing to do the Arcane U quest series. However, the easiest place to buy a low level version is Warlock's Luck in Bravil.

Mara

if you spam the light spell some you can get enough skill pretty quickly to cast Void Gazer that the cat dude sells in the DB. it is fairly costly but is the best ne spell in the game. it would take about 3-4 times the magicka if you made a similar spell, which you can't because you can only make 120 sec spells. it V.G. takes about 40 magicka at 25 illusion and last like 240 secs.

You killed Lucien?

I killed him to. CRIMINAL SCUM!

Oh, I was just trying to figure out the WHY behind that decision.

Engimatic as Lucien was, I did the same when he started yelling at me about offing the entire DB. I was like, "you little Imperial Girl" and Norded him all over Bravil.