Working on another project I found this amidst my notes:
When you take time (a few hours) to concoct a strange elixir name a monster and pick 1 effect:
• Consuming the elixir forces you into a coma from which you won’t wake for several hours.
• The elixir wracks your body with pain as it works on your system. Take 1D8 damage.
• The elixir’s effects will last for less than an hour, rather than a few hours.
Then roll + CON. On a 10+ hold 3. On a 7-9 hold 2. On a 6- hold 1, but the GM chooses an additional effect from the above options. While the elixir is in your system you may spend your hold to to negate the effects of the chosen monster’s abilities on yourself. You can resist a vampire’s mind control, match a werewolf’s agility, stop a gorgon from turning you to stone, etc.