Seriously, put yourself into my situation and be of any use.

[rvg]

It's pretty simple, a friend wants to commit suicide but wants to kill his farther first. I know why and I would have killed him allready. I am trying to talk him out out of everything he plans to do but he is really smart, much smarter than me and can counter anything I come up with. Should I warn his father who is a horrible person or should I just pretend I never knew. I'm not sure. I am pretty sure my friend is serious, and he is way too intelligent to make social-workers change his mind.

So advice

What's more important to him, killing his father or killing himself? Whichever you think is more important to him, that's what you need to talk him out of, the other part would fall off on its own.

If it's suicide, then I don't know, take him out to dinner or something, give him a chance to have some fun. That generally puts the suicide ideas on hold.

If it's killing his father, then maybe you can stress that very few people are beyond redemption, no matter how bad they've been.

This is just to buy you some time. In the meantime, you might wanna contact the authorities, this guy needs serious help.