Like so?
Arrow Storm (Ex): A sluagh can release a volley of tiny arrows as an area attack. The sluagh may choose to release either a 30-foot burst to a maximum range of 1,000 feet, or a 100-foot cone. Regardless of the shape, the arrow storm deals 3d6 points of piercing damage (Reflex DC X half). The save DC is Dexterity-based.
Envenom Arrows (Su): Three times per day, a sluagh may choose to envenom its arrow storm. Any creature damaged by the arrow storm is exposed to the sluagh's poison.
Sluagh Arrow Poison: Injury, Fortitude DC X, initial damage 1d10 Con, secondary damage curse. The curse functions similiar to the bestow curse spell (sluagh's choice of curse). The save DC is Charisma-based and includes a +X racial bonus.
Did you prefer the name "Elf-shot" for one of the abilities?