Imp + Soul = ???

[BaconAwesome]

In a game I'm running, a PC has entered a familiar contract with an imp. For game balance purposes, I've ruled that if the PC tries to share magic resistance or do remote viewing without an LE alignment, the shock of mental contact requires a wisdom save to avoid stunning.

Unbeknownst to the players, the imp was originally a human child whose soul was sacrificed in a ritual, and the players may have a chance to free her soul.

I'd love suggestions on what happens next. I'm planning to keep the contract in place but free the familiar from direct infernal control. Additional possibilities:

1) Change the stat block to an imp or some similar CR creature?

2) Start a plotline where the imp's old boss is out to get her and her master?

[Endal]

I agree that you should adjust the stat block for the Imp/Child. This is basically a character NPC and should be given extras.

As for what happens next, I'd let your players decide. Give them enough backstory so that they can understand what's happening and what the options are. I like the idea of the original owner coming back to claim the imp and I'd send some other imps at them to try to reclaim her. Players beat up the other imps and the story can unfold.

My method with my players is always to give them true options in the story and let them choose their own adventures, then I just react to those options (or to them throwing the options out the window and starting up a panini truck).

[Nagog]

I'd adjust the alignment, but that's about it. Changing their physical form may have unforeseen complications if they still want this child as their familiar, but as to my knowledge the alignment of a familiar doesn't change anything at all. Also imps are great familiars in general, so making them a human child again nerfs that heavily, as well as changes them from a familiar to a magically bound slave, which may end up changing your character's alignment in the eyes of many people XD

[Envyus]

Unless you want to make changes, for the most part the Imp should have nothing in common with the soul it was created from. Gender, memories, personality. None of that would have stayed with the Imp itself.

If you free the soul from the Imp I would change the statblock as it's not the same creature anymore.