I would like to create a mentally deranged character. Someone prone to violence (not just the complete and total slaughter of everyone in the Mojave) and bouts of insanity.

I'm clueless about any kind of SPECIAL or perks (other than Terrifying Presence) or even where my focus should be. I would like to side with Black Mountain (not sure that's even remotely possible) and hang out with No-Bark most of the time, but other than that...

Help please.

Maybe have some kind of trigger word that everytime someone says it in dialouge you exit as soon as possible and just go psycho on everyone around you? I dont know man but it sounds like a pretty cool role play.

L[censored]IPAM (laughed so hard I thought I think I pulled a muscle)

Yes it could be "I want you to..." First faction to give me some assigment get's to die horribly.

Lower your INT to 4. Then you'll get the "dumb" character options to add to the mix. And don't forget running around with a Rolling Pin!