Nefer is a Lunar-Bloom DPS that primarily deals damage through her enhanced Charged Attacks while in the Shadow Dance state. Nefer's enhanced Charged Attacks consume Verdant Dew, and summon Shades that deal Lunar-Bloom Damage as coordinated attacks. Nefer also converts Bloom Cores into Seeds of Deceit, which enhances her Skill and Burst depending on how many she has consumed. The conversion requires Moonsign: Ascendant Gleam to be active.
Seeds of Deceit do not deal damage, and they cannot enable Hyperbloom or Burgeon. They are strictly to enhance Nefer's Burst and add Lunar% buffs to her Skill.
Regarding Weapon Choices:
Sunny Morning Sleep-In: Ranking assumes the Skill Elemental Mastery buff and part of the Burst Elemental Mastery buff.
Dawning Frost: At [R5], this weapon will perform better than .
The Widsith: This weapon loses a lot of value if Nefer does not aquire the Elemental Mastery buff. Assuming she does get it, at [R5], this weapon will perform better than .