Is it possible to prevent the slime ball from getting away when you first bring it to Linda? I've failed the Nim skill check twice at 68% and 82% respectively, so I'm not sure if it's programmed to fail or if I'm just unlucky.
You're just unlucky. I've had a 93% chance of succeeding fail, I've also had really low chances of succeeding work (25% chance, and it worked). Indivi will be able to answer if it's meant to fail though. There's some stuff (dealing with the Succubus Queen) that even if you pass the check, you still need to go through with what the Queen has planned...