Can anyone explain why and how to use illusion spells as a rogue/assassin type character? I love the idea, but honestly don't see how illusion would help me when sneaking through a cave/fort/etc. Sure, invisibility might be useful, but that's just one spell out of several, and doesnt look to be worth the perks needed to spec in illusion. Please explain any strategies or general reasons how illusion can be useful to a rogue. Thanks.

I was thinking either illusion or alteration on my assassin. I haven't started using either yet though since I wanted to build sneak and some weapon skills first. Illusion also has calm and frenzy I believe. Both of those would help an assassin quite a lot as well. Calm your target for a free kill pretty much. Frenzy a group of people so you, yourself, don't have to fight a room full of baddies.

I;ve been using illusion with my rogue character. There is a muffle spell which is helpful to keep your footsteps quiet. I use that constantly. Calm or Fear work well for when you get stuck in close combat. Frenzy is helpful for turning distant foes on each other. Invisibility is the "holy grail", but I'm not high enough level yet to find that spell. Clairvoyance is helpful for finding your objectives in dark caverns.

I also haven't been able to find nighteye--I don't think it made it into the game. It's too bad really, it was one of my favorites in the past. It's also lame that Detect Life, and Paralyze are part of Alteration now because I cant afford perks in both Illusion and Alteration...