  The K\"ahler potentials of modular symmetry models receive unsuppressed
contributions which may be controlled by a flavor symmetry, where the
combination of the two symmetry types is referred to as eclectic flavor
symmetry. After briefly reviewing the consistency conditions of eclectic flavor
symmetry models, including with generalised (g)CP, we perform a comprehensive
bottom-up study of eclectic flavor symmetry models based on $\Omega(1)\cong
\Delta(27)\rtimes T^\prime$, consisting of the flavor symmetry $\Delta(27)$ in
a semi-direct product with the modular symmetry $T^\prime$. The modular
transformations of different $\Delta(27)$ multiplets are given by solving the
consistency condition. The eight nontrivial singlets of $\Delta(27)$ are
related by $T'$ modular symmetry, and they have to be present or absent
simultaneously in any $\Omega(1)$ model. The most general forms of the
superpotential and K\"ahler potential invariant under $\Omega(1)$ are
discussed, and the corresponding fermion mass matrices are presented. Based on
the eclectic flavor group $\Omega(1)$, two concrete lepton models which can
successfully describe the experimental data of lepton masses and mixing
parameters are constructed. For the two models without gCP, all six mixing
parameters vary in small regions. A nearly maximal atmospheric mixing angle
$\theta_{23}$ and Dirac CP phase $\delta_{CP}$ are obtained in the first model.
After considering the compatible gCP symmetry and the assumption of $\Re
\tau=0$ in the first model, the $\mu-\tau$ reflection symmetry is preserved in
the charged lepton diagonal basis. As a consequence, the atmospheric mixing
angle and Dirac CP phase are predicted to be maximal, and two Majorana CP
phases are predicted to be $\pi$.
