So I'm on my second proper playthrough, first time round I was a conjuration/destruction mage, this time I'm a stealth archer/dual dagger/thief/assasin/ninja/general badass!

I love being able to take out an entire fortress of bandits without being hit once. Not only have my archery and sneak skills increased dramatically from just two of these, my play time has too (it takes so long!)

My last playthough, I was a bit of a goodie-two-shoes, helping everyone and making (what I thought were) morally right decisions.

I want to turn that around, join the dark brotherhood or the thieve's guild. BUT I have already wronged my first person - Cicero. Watching the guard scold him for a murder that never took place genuinely made me feel like an awful person!

Anyone else feel like this on their first "evil" playthrough or am I just too invested in this game!?

If no one has said this, welcome to the forums. Here is a fishy stick for you: http://www.uesp.net/wiki/General:Fishy_Stick

I usually play morally 'good' characters, too.

I kind of felt that way the first time I played the Dark Brotherhood in Oblivion. It was the very first time I had played an 'evil' character (ever) and I guess it did make me feel a little guilty? I am not sure if that's the right feeling, but yes? After I kept reminding myself this is only a game, I started to get into it and go with the character. It turned out to be quite a bit of fun.

Also if this is the situation I am thinking it is, keep in mind there different choices you can make that have different outcomes.

I once had a casually cruel character whom I could barely stomach to play. She genuinely enjoyed making people suffer. It felt strange, to say the least. Not something I'm likely to repeat. My other evil-doers typically had more gray morality: a soldier struggling with the dark side of newly acquired vampirism, a war refugee with a hardened heart. I could sympathize with them.