  We study the non-standard interactions of neutrinos with light leptonic
scalars ($\phi$) in a global $(B-L)$-conserved ultraviolet (UV)-complete model.
The model utilizes Type-II seesaw motivated neutrino interactions with an
$SU(2)_L$-triplet scalar, along with an additional singlet in the scalar
sector. This UV-completion leads to an enriched spectrum and consequently new
observable signatures. We examine the low-energy lepton flavor violation
constraints, as well as the perturbativity and unitarity constraints on the
model parameters. Then we lay out a search strategy for the unique signature of
the model resulting from the leptonic scalars at the hadron colliders via the
processes $H^{\pm\pm} \to W^\pm W^\pm \phi$ and $H^\pm \to W^\pm \phi$ for both
small and large leptonic Yukawa coupling cases. We find that via these
associated production processes at the HL-LHC, the prospects of doubly-charged
scalar $H^{\pm\pm}$ can reach up to 800 (500) GeV and 1.1 (0.8) TeV at the
$2\sigma \ (5\sigma)$ significance for small and large Yukawa couplings,
respectively. A future 100 TeV hadron collider will further increase the mass
reaches up to 3.8 (2.6) TeV and 4 (2.7) TeV, at the $2\sigma \ (5\sigma)$
significance, respectively. We also demonstrate that the mass of $\phi$ can be
determined at about 10% accuracy at the LHC for the large Yukawa coupling case
even though it escapes as missing energy from the detectors.
