Disciplines: icondisanimalism icondispresence icondisspiritus
Sect: Sabbat
Nickname: Cats
The Ahrimanes originated with the Sabbat Gangrel. The founder of this bloodline was a Gangrel antitribu named Muricia. When Muricia utilized the thaumaturgic powers of the native North American shamans, she effectively separated herself from her clan and her blood forever altered.
Muricia tried to create others like herself, but soon discovered she could not, for her vitae was infertile. She learned she could choose existing Gangrels and, using the same ritual the shamans used on her, make them like her.

icondisspiritus The Ahrimanes have a new discipline: Spiritus. This discipline comes from the spiritual forces existing in nature. This discipline is highly versatile, giving Ahrimanes a strong edge over other Kindred in the wilderness.

-- Storytellers Handbook to the Sabbat
  V:TES Notes  
The Ahrimanes cards mix well with the Gangrel and (to a lesser extent) the Toreador and Brujah (as well as those clans' antitribu counterparts). Although their numbers are small, you could also play the Ahrimanes by themselves. They're stronger when mixed with other clans, usually.

New Term:

Sterile vampires cannot take actions to create other vampires (e.g., cannot perform The Embrace action, The Third Tradition action, etc.). These vampires cannot perform the Revelations of the Sire or the Abomination actions, either.

  Card Preview  
Feral Spirit
Put this card on any Gangrel or Gangrel antitribu you control. This vampire is now an Ahrimane (and Sabbat). This vampire has Spiritus; if the vampire already had Spiritus, he or she now has superior Spiritus. This vampire is now Sterile.
This is another card designed for mixing Bloodlines clans with other clans.
With Feral Spirit you can turn one of your "basic" vampires into an Ahrimane. That vampire will then be able to play cards that require Ahrimanes as well as cards that require Spiritus. (If you change his clan back to Gangrel with Clan Impersonation, you could then play another Feral Spirit to give him superior Spiritus. A complicated way of simulating a Master: Discipline card, but it's there if you want to try.)
Since there's no clan requirement on this card, you don't have to control your Ahrimane vampire first. You could even play this card with no Ahrimanes in your crypt at all (and "build your own" Ahrimanes from the plentiful Gangrel and Gangrel antitibu vampires).