My thoughts:
Entropy Nymph: Targets a player, whoever the player votes for get -2 votes. Too close to liar.
Death Nymph: Target player loses 2 votes a day. When they reach zero they start getting plus 1/2 vote each day. ??? Don't get what you are trying to say.
Gravity Nymph: All people targeted for lynching lose 1 vote. Might be a little OP
Earth Nymph: Target player is "Burrowed" for three turns.Little OP
Life Nymph: Target player can now vote twice a day.OP
Fire nymph: Target player gets +2 votes but +2 votes on the lynching board.OK
Water Nymph: Target player gets a nymph ability. Fallen Elf, just more specific.
Light nymph: ???
Air nymph: Target player gets +2 votes on the lynch board and all other targets get +1. Other targets? Does that mean all other players? If so, you just give primary target 1 extra vote.
Time nymph: ???
Dark Nymph: ???
Aether Nymph: Can target a player every third turn. That player gains immortal. Waaay OP. Target yourself every 3 rounds!