Recent advancements on observations of the transient sky have led to the unveiling of numerous events that challenge our understanding of the thermonuclear explosion paradigm. While the majority of these transients can be explained in the standard carbon/oxygen white dwarf (C/O WD) binary progenitor system, leading to "normal" Type Ia SNe (SNe Ia), thermonuclear explosions with observational properties that differ from "normal" SNe Ia need to be explained by pushing the thermonuclear explosion scenario to its limits. One of the most enigmatic sub-class is the "Super-Chandrasekhar" Type Ia SNe (SC SNe Ia), rare events of enormous luminosities, broad light curves and relatively low ejecta velocities, that stand in conflict with the classical Chandrasekhar-mass explosions, as they require larger ejecta, and occasionally synthesised nickel, masses. Moreover, as more SC SNe Ia are discovered, the intrinsic diversity within this sub-class is becoming more prevalent, adding additional questions to the SC SNe Ia mass puzzle. As new and more powerful time domain surveys are on the way, the need for a complete explanation of these extreme events is crucial, not only from a stellar evolution perspective, but also from a cosmological point of view, as these events may contaminate cosmologically-useful samples of SNe Ia. In this talk, I will review our current theoretical understanding of the progenitor system of SC SNe Ia and their explosion mechanism, in conjunction with the "well-behaved" SNe Ia, and present high-quality observations and subsequent studies of recently discovered members of this sub-class, that provide insights on their true nature.