謎之

谜之
mízhī
(neologism) (slang) (attributive) mysterious; enigmatic (calque from Japanese 謎の "nazo no")

CEDICT

neologism slang

Entry Composition

1 謎 mí riddle
2 之 zhī
  1. (possessive particle, literary equivalent of 的 de)
  2. him
  3. her
  4. it