I meant to like this already. Fixed. Really good theme, and the writing really sells the RP throughout. As a follower of Sheogorath, I approve. Marching Feast is full of juicy RP goodness.

A lair that offers "suitably dismal living space" 

Thanks :D. Despite how much I love RP, I have a nasty habit of just trying to horde gold, gear and power in games like Skyrim. I'm hoping developing some builds will help break that habit, so the RP will keep flowing as time goes on. I'm hoping to add another RP influenced ability soon. My last shot at testing it was foiled by the Ash spells being too good at what they do.

Updated with a new (RP focused) combat ability, and the Spider's very own theme music (conveniently at the top in case you don't want to listen).

Was already a very nice build, but yay updates! +1 from me 

Another update! Thanks to Curse Never Dying for explaining a simple item duplication glitch that solves the problem with limited Spider scrolls. It requires a follower, though, so I recommend Cicero since he could well be as crazy as the Spider. Ralis Sedarys, already on Solstheim and pretty clearly addled in the head, is also an option, but any follower could do (temporarily).

I've been looking for a good build. With spiders as my favourite animal, this interested me. GREAT build!

Thanks a lot, Ben :)

I've only tested it once, and not on the Spider as testing other builds has been time consuming, but yes it worked fine. For me the trick is restraining myself from going overboard. Sometime, though, I'm going to have to find out just how much of the gameworld I can overrun with only mind control spiders.

Thanks a ton Rob, that means quite a lot!