Lower numbers mean a harder to utilize immortality flaw. More personalized immortality flaws are generally considered more difficult. Elementalism with its low barrier to entry may be the least popular form of immortality in setting.
Difficulty Estimate
1. Glory(Learning the ritual associated with your target. Incapacitating your target. Successfully performing the ritual upon your target.)
2. Oneiromancy(Learning the specific dreamworld. Acquiring a weapon made there. Killing the enemy with it.)
3. Arete(Acquiring a sample of your target viable for cloning, acquiring an animating force for the clone, and sending it to fight your target. Making a rope of your target's hair and choking them with it).
4. Earthpower(Learning the specific plant your target chose. Acquiring the plant assuming it cannot be simply conjured. Poisoning your target with it).
5. Alchemy(You need a blood sample from your target or data on how their immortality elixir was made to make a poison they instinctively recognize)
6. Necromancy(Acquiring Tradition appropriate materials to your target. Incapacitating your target. Stuffing them into your target's mouth)
7. Elementalism(Incapacitation and binding of your target. Bringing them through a travel grid portal leading into space and throwing them out the other side)
