UngeheuerLich
Legend
I think this would work in general. The powers granted by Archfey, hexblade, undying, Fiend, great Old Ones and even the fathomless seem like they would be more or less universally applicable. I can see almost any patron granting mind-affecting/mind-shielding, melee/luck powers, semi-immortality, resistance/luck, telepathy/mind-control or sea powers.
I could even see patrons giving out a phylactery with Genie's powers but doing so would mean Genie loses almost all unique flavor.
The exception is Celestial's powers. While applicable to many, Radiance & healing seems off for evil/darkness patrons.
Pact and patron can easily be swapped in power, if you are ok with a bit less backward compatibility.
The celestial powers could be relegated to invocations with prerequisite: celestial patron.