Sorcerer On the Rocks

Also known as "Chivas (or Shibas) 1-2-3".

Ruthless sorcerer Shibas Scotch is employed by a count named Cuttlefish to subdue a beast terrorizing the city. In his first run-in with the monster, Shibas is unable to return his soul to his own body and instead transfers it to that of his (female) servant, Gin Fizz.

This two-episode OVA is set in the same world as Sorcerer Hunters, although you do not need to have watched or read that to understand what's going on.

Tropes used in Sorcerer On the Rocks include:

Allergic to Evil: Gin Fizz (apparently) gets ill whenever they're in a bad place, like a seedy town full of whorehouses and casinos.
Anti-Hero: Shibas Scotch is such a bad person that being in a "good" place like a clear field or meadow makes him ill.
The Chick: Fizz, when Shibas isn't in control of her body.
Executive Meddling: It was originally titled "Chivas 1-2-3"', but was renamed to avoid a lawsuit with a well-known whiskey company.
Our Werewolves Are Different: Kiss
Sharing a Body: Shibas and Fizz, once he loses his Soul Jar. Apparently, it happens so often that no one in the group was surprised.
Spell My Name with an "S": Shibas or Chivas?
Soul Jar
Theme Naming: Shibas Scotch, Gin Fizz, Million Dollar, the list goes on...