El Gordo is one of the most extreme objects in the Universe. It is a massive merging galaxy cluster at z=0.87 which hosts the most distant complex of diffuse cluster-scale radio emission observed in the intra-cluster medium: two relics and a giant radio halo. The presence of powerful cluster-scale radio emission at this redshift challenges current theoretical models since most of the energy of relativistic electrons is radiated away efficiently via inverse Compton scattering of the cosmic microwave background. I will report the discovery in this system of a strong shock that is spatially coincident with the NW radio relic. This shock may be powerful enough to accelerate relativistic particles directly from the thermal pool, contrary to the majority of relics for which the presence of a pre-existing population of relativistic electrons is generally invoked. I will discuss how the presence of strong merger shocks in El Gordo combined with the extreme dynamics of the cluster may allow to reconcile observations with theoretical models.