  We consider flux compactifications of type IIB string theory and F-theory in
which the respective superpotentials at large complex structure are dominated
by cubic or quartic terms in the complex structure moduli. In this limit, the
low-energy effective theory for the complex structure and axio-dilaton sector
exhibits universal properties that are insensitive to the details of the
compactification manifold or the flux configuration. We show that there are no
vacua in this region and the spectrum of the Hessian matrix is highly peaked
and consists only of three distinct eigenvalues ($0$, $2m_{3/2}^2$ and
$8m_{3/2}^2$), independently of the number of moduli. We briefly comment on how
the inclusion of K\"ahler moduli affect these findings. Our results generalise
those of Brodie & Marsh [1], in which these universal properties were found in
a subspace of the large complex structure limit of type IIB compactifications.
