A call to all Rules lawyers and contract specialists I need help
So I’m in a campaign with a soul collecting demon lord, whose primary goal is to collect the souls of the entire party. he already has two and set up my character for a slow burn mid to late campaign collection should I give in. Now I play an aasimar  corrupted by a vampire bite so technically fallen but not if you know what I mean (protector Aasimar damphier hybrid)(Domain of blood cleric rogue assassin)  basically a justicar(definitely didn’t spell that right) /temple assassin in-service to the goddess of war soldiers and Justice. and this demon lord is a contract specialist. Due to events in the campaign Several of our party needed to disguise themselves due to a quest in which our party needed to enter a foreign country with a severe opposition to magic specifically they employ mage hunters One of our tiefling‘s while in my presence requested this disguise from his patron a.k.a. the demon lord who we all know as shade now our tiefling did not specify the disguise other than to blend in and be able to swim so he’s patron utilizing my characters biggest weakness Ultra cute fluffy things temporarily permanently (if he doesn’t fulfill the bargain he remains in this form( Collect the soul of the regent of the country we are headed to who is in league with one of the big bad cults And has escaped my goddess is justice) Transformed our Centaur tiefling Into a super cute fluffy female jackalope  A.k.a. my characters perfect addiction  so far this demon lord has only requested the souls of sinners and those who have escaped justice So in essence working within the confines of my goddesses (mandate? Can’t really think of a good word here) but I think you’ll get my meaning So what I’m asking is to gather my rules lawyers and contract specialists and help me create a situation in which I have a full proof contract ready for the temptation of sad demon lord because odds are He’s going to corrupt the party And I’m trying to figure out a way to keep my soul my own and pure while still reaping the benefits That he offers My friends I set you this task Do not fail me For I wish to have my bunny girl cake and eat it too
And on a sidenote I can’t even kill this guy without violating my goddesses tenants
Now even should a party get together with a deity or somesuch to kill said demon lord he is “completely innocent of sin” and therefore I would be violating the tenants of my Goddess by killing him