Elven Vampire

Alas! Child of light,
No more shalt thou see the stars
Wheeling in Heaven.

Crooked hands; the rose
Withers at thy touch, the tree
Turns her face, shudders.

-From Narthang eolinde, a Sithican book of poetry
Elven vampires are hideously scarred mockeries of the grace and beauty they exemplified in life.
An elven vampire is cursed with a "black thumb." Any plant they touch rots away and dies, with the vampire feeling its pain all the while. Emyr believes the process to be irreversible; he can't cure any plant once he's touched it, even if it's only dying rather than dead. No one other than him has ever tried, however, so it may only be that the vampire itself can't cure the plant.
Unlike other strains of vampire, elven vampires are diurnal, with the night harming them rather than the day. Due to Emyr's unique curse, however, the night returns his conscience rather than harming him. Unfortunately, it also seems to make him bestial, incoherent, and thoroughly mad.

Known powers and immunities

Instead of blood, elven vampires feed on the personality and creative energies of their prey (Charisma damage), marking them with grotesque scars similar to their own; you don't know if they drain every living creature they touch, or if they have to make an attack. (Emyr struck you every time he drained you, but you don't know if that was necessary or if he was just in a fighting mood).

Emyr appeared to leave you with something similar to tree stride, but without using verbal or somatic components, so it appears to be an innate ability of elven vampires rather than a druidic spell. The tree rotted and died before your eyes when he used it. (This is how elven vampires beat a hasty retreat rather than gaseous form. The theming on these things is just beautiful.)
Judging by how he shrugged off the crocodiles' attacks, Emyr has damage reduction (I think the most one of them did was 13 damage, and it didn't leave a scratch he was resistant to call lightning as well, although not as much as physical damage. Vanya's magic sword hurt him badly. Sound burst did normal damage, but undead are immune to stun.