I was testing out all the different things they do. Once I was done I removed the optional feature. Now my character has an immunity to poison and vulnerability to psychic from dark bargain.

I can't remove it at all, and enabling dark bargain again gives me nothing 

Finally got it to put up with the options. 

If you disable the dark bargins while one is active, the effects can be still in effect. So remember to remove whatever dark bargain you have before disabling the features.