Namharim, Born of Night is a Vivid Harvest boss.
Vivid Scalefruit is a Tier 4 Harvest Seed. When harvesting the seed, it will spawn the boss Namharim, Born of Night.
While growing a tier 4 seed is difficult, defeating Namharim, Born of Night is easy.
HHC 3.11 Vivid Boss Namharim, Born of Night