  Rich physics can be divined from charged black holes subjected to extremal
conditions. When applied in conjunction with principles like Weak Cosmic
Censorship, this naturally leads to constraints on the mass and charge of the
black hole. However, more nuanced principles such as the Weak Gravity
Conjecture (WGC) and the recently proposed Festina-Lente (FL) bound can
provide, respectively, upper and lower bounds on elementary charged particles.
In this study, we examine the quasinormal modes (QNMs) exhibited by a massive
scalar test field carrying an electric charge, oscillating in the outer region
of the black hole. These modes are subjected to the constraints imposed by the
FL and WGC bounds. Our analysis provides insight into the behaviour of QNMs,
particularly in regions that approach the extremal conditions of the black
hole. Notably, in these regimes, the stability of the modes becomes precarious,
particularly in the presence of a positive cosmological constant. The
implications of our findings are far-reaching and significant. They extend from
safeguarding the principles of cosmic censorship to addressing the structural
stability of the black hole's interior. Our semi-classical analysis presents
compelling evidence suggesting that Strong Cosmic Censorship may be violated
for black holes that are in close proximity to extremality within the context
of Reissner-Nordstr\"om-de Sitter (RNdS) geometries.
