Reasonable, I originally wanted a Reverend Insanity x Lord of the Mysteries fanfic but then I realized that I have to reread RI again and my motivation might become different after I reread it. So it went to a cultivation novel instead.
If you're a Demoness then you're set. It also depends on what the Outer Deity is since they could combat against any powers. As for an upfront seduction, there are no conventional ways since you'll lose control buuuuuut. According to Sucker for Love, you might want to try sacrificing to the Outer Deity and rizz them in that way (might lead to the destruction of your world)