In my old campaign I had a few interesting characters. One was a scion, a bastard child of a human and a Denarian. She was raised by the Denarians as a kind of infiltration/black ops agent and was planted into the mortal mafia. She also had an IoP dubbed a Hellfire Sword, which was made by the Denarians as a means to allow important non-Denarians the ability to fight against the Knights of the Cross and other supernatural opposition.
I had made a PC that ended up (unwillingly) bound to a sort of trickster demon named Whisper that only he can see and hear. The binding granted him powers, but the demon was always following him around and generally making his life as miserable (and dangerous) as possible.
We also had a pure mortal who was essentially a supernatural black market arms dealer, which made him considerably wealthy. He had a custom made magnum revolver and custom made ammo for dealing with various supernatural threats. Like iron/steel bullets for the Sidhe, "ghost" bullets (bullets made with the same type of ghost dust Harry used in GP), bullets anointed in holy water and blessed by a priest, rubber bullets for non-lethal means, ect. He also had a cache of powerful supernatural artifacts which was an easy justification for temporary powers. It was also a convenient all-purpose story hook for me haha.