  Observations of Type Ia supernovae (SNe\,Ia) reveal diversity, even within
assumed subcategories. Here, the composition of the peculiar iPTF16abc
(SN\,2016bln) is derived by modeling a time series of optical spectra.
iPTF16abc's early spectra combine traits of SNe 1999aa and 1991T known for weak
\SiII\ $\lambda$ 6355 and prominent \FeIII\ features. However, it differs with
weak early \FeIII\ lines, and persistent \CII\ lines post-peak. It also
exhibits a weak \CaII\ H\&K feature aligning it with SN\,1991T, an observation
supported by their bolometric light curves. The early attenuation of \FeIII\
results from abundance effect. The weakening of the \SiII\ $\lambda$ 6355 line,
stems from silicon depletion in the outer shells, a characteristic shared by
both SNe 1999aa and 1991T, indicating a common explosion mechanism that
terminates nuclear burning at around 12000 \kms\, unseen in normal events.
Beneath a thin layer of intermediate mass elements (IMEs) with a total mass of
0.18 \Msun, extends a \Nifs\ rich shell totaling 0.76 \Msun\ and generating a
bolometric luminosity as high as ${L_{\mathrm{peak}}}=1.60 \pm 0.1 \times$
$10^{43}$ ergs s$^{-1}$. Inner layers, typical of SNe\,Ia, hold neutron-rich
elements, (\Feff\ and \Nife), totaling 0.20 M${\odot}$. Stable iron, exceeding
solar abundance, and carbon, coexist in the outermost layers, challenging
existing explosion models. The presence of carbon down to $v\approx$
9000\,\kms, totalling $\sim$ 0.01 \Msun\, unprecedented in this class, links
iPTF16abc to SN\,2003fg-like events. The retention of 91T-like traits in
iPTF16abc underscores its importance in understanding the diversity of SNe\,Ia.
