  With the launch of JWST and other scheduled missions aimed at probing the
distant Universe, we are entering a new promising era for high-$z$ astronomy.
One of our main goals is the detection of the first population of stars
(Population III or Pop III stars), and models suggest that Pop III star
formation is allowed well into the Epoch of Reionization (EoR), rendering this
an attainable achievement. In this paper, we focus on our chance of detecting
massive Pop IIIs at the moment of their death as Pair-Instability Supernovae
(PISNe). We estimate the probability of discovering PISNe during the EoR in
galaxies with different stellar masses ($7.5 \leq
\mathrm{Log}(M_\star/\mathrm{M_\odot}) \leq 10.5$) from six dustyGadget
simulations of $50h^{-1}$ cMpc per side. We further assess the expected number
of PISNe in surveys with JWST/NIRCam and Roman/WFI. On average, less than one
PISN is expected in all examined JWST fields at $z \simeq 8$ with $\Delta z =
1$, and O(1) PISN may be found in a $\sim 1$ deg$^2$ Roman field in the
best-case scenario, although different assumptions on the Pop III IMF and/or
Pop III star-formation efficiency can decrease this number substantially.
Including the contribution from unresolved low-mass halos holds the potential
for increased discoveries. JWST/NIRCam and Roman/WFI allow the detection of
massive-progenitor ($\sim 250 ~ \mathrm{M_\odot}$) PISNe throughout all the
optimal F200W-F356W, F277W-F444W, and F158-F213 colors. PISNe are also
predominantly located at the outskirts of their hosting haloes, facilitating
the disentangling of underlying stellar emission thanks to the
spatial-resolution capabilities of the instruments.
